Rakanma ½

Disclaimer: Ranma ½ belongs to Rumiko Takahashi, a huge fan of the "Belligerent Sexual Tension" trope. Therefore, I am clearly not Rumiko Takahashi.

Formatting Notes: Double quotes indicate spoken dialogue, while single quotes indicate thoughts. Italics indicate flashbacks. I'm not very familiar with Japanese honorifics, so I won't be using them except in the cases of Ranma's and Ukyo's childhood nicknames for each other and of course the name of Ukyo's restaurant. I will also be using English translations for most terms except for the technique names that are left untranslated in the animé. As for the Amazon names, the naming theme can't be a coincidence (as with the Musk naming theme). I feel that the Chinese Amazons purposely name their children after the English words for hygiene products and then write the names as the closest Chinese equivalent. Therefore, they will have the same names even when speaking to each other in Chinese in the context of the story. As for gender pronouns when referring to Ranma, the narration will refer to Ranma by his current form, while the other characters (except the Kuno siblings) will think of him as male and speak of him as male, unless they have some reason to hide his curse at a point when he's female.

Prologue: Sins of the Father

10 year old Ranma Saotome was very nervous as he followed his father, Genma Saotome, to the guide's hut in the Chinese valley of Jusenkyo. After the horrific experience of the Cat Fist training the month before, he was beginning to wonder if his father really cared for him. Even though his father had missed the warning on the next page of the training manual, he had been shocked at what his father had been willing to do to him for the sake of a martial arts technique. He was getting the idea that this "legendary training ground" was another bad idea.

As far back as he could remember, he and his father had been constantly traveling as they trained in martial arts. It wasn't all bad, as he did love martial arts, and his father was admittedly an excellent martial artist and a good enough teacher to develop his natural talent to the point where he was already superior to many of the masters with whom he had trained. However, he was beginning to realize the price he had paid to reach that level. He hadn't thought about it much before, but the Cat Fist training had opened his eyes. Surely, martial arts training didn't require having your food stolen by a sensei who was already overweight, forcing you to go to bed hungry, did it? There were also several of his father's training methods that were a lot more dangerous than he thought they really needed to be. It also didn't help that their constant traveling had left him without a home and with very few chances to make friends.

As they approached the hut, an overweight Chinese man in some kind of uniform came out and greeted them in broken Japanese, apparently able to recognize the nationality of his approaching guests. "Greetings, honored guests. Welcome to Legendary Training Ground of Jusenkyo. Please, sign visitors' log and I tell you about springs." After they signed in, he continued. "You very strange ones, no? Not many people come to Jusenkyo these days. It very dangerous. There over 100 cursed spring here, each with its own tragic legend."

Genma grunted. "A martial artist must be prepared to give his life for the Art. Come, Ranma." He jumped on top of one of the many bamboo poles sticking out of the springs of water. However, warning bells had started going off in Ranma's head. 'Did he say 'cursed?'' As he stood there in indecision, Genma shouted, "What's keepin' you, boy? Are you afraid of a little water? Stop acting like a girl." His favorite insult to his son was enough to get Ranma to join him on another bamboo pole. "Don't call me that, Pop!" Genma once again winced at the reminder that his son had taken to calling him "Pop" instead of "Daddy" after the Cat Fist training the month before.

The Jusenkyo Guide tried in desperation to warn them. "Sirs, what you doing? I not finished with tale of tragic legend." However, the two fighters had stopped listening to him. After a few blows, Ranma succeeded in knocking his father into one of the springs. However, what emerged from the spring was not a middle-aged, overweight, bald man but a panda still wearing Genma's gi and glasses. Ranma was stunned as the guide explained, "Ah, too bad, you fall in Spring of Drowned Panda. There a very tragic legend of a panda who drown there two thousand year ago. Now, whoever fall in spring take body of panda."

As the idea of having a panda for a father took hold, Ranma stammered, "W-wait a m-minute. You never said anything about…" In his distracted state, he didn't notice that his father-turned-panda wanted to continue the fight. A huge paw hit Ranma and sent him flying into one of the other springs. In the water of the spring, he felt some kind of force take hold of his body. He swam for the surface and breached the top of the water. He slowly opened his eyes and looked down at his body, afraid of what he would see. He let out a sigh of relief, as he was still human. The guide was saying something, probably about the spring he had fallen in, but he couldn't make it out with the water currently in his ears.

As he climbed out and made his way back to the hut, he did notice a few differences. His pigtail had landed on his shoulder and revealed that his hair color had shifted to a bright red. His voice was a little higher. He was also a few centimeters shorter, something he wouldn't have even noticed without his background in martial arts. If that was all the cursed spring had done to him, then for once he had gotten off lucky.

Back in the hut, the guide served tea and began explaining more about the curses. He told them that the curse was not permanent but neither was it temporary. Cold water would activate the curse, while hot water would restore their natural forms. In demonstration, he poured some hot water from the kettle over the panda to restore the familiar human form of Genma Saotome.

At first, Ranma couldn't understand the sorrowful look in his once again human father's eyes as he looked at what had become of his son, like his curse was somehow even worse than turning into a panda. The guide was about to pour hot water on him as well when Ranma decided he first needed to take care of a certain problem. "Wait just a minute. I'll be right back, but I need to go pee." He rushed out the door, while Genma watched in confusion. The guide said, "I think maybe he not realize yet. Not as easy to tell at that age. Well, he know now." The guide had no sooner finished speaking these words when the sound of a huge female scream pierced the morning air.

A couple of minutes later, an enraged female Ranma reentered the hut, her eyes full of tears for the first time since they had left on their trip four years ago. She grabbed a chair and began smashing it over Genma's head. "YOU IDIOT! You've turned me into a girl! It don't matter that I can sometimes change back. You've ruined my life! I was prepared to give my life for the Art but not my manhood. This is the last straw! I'm leavin' an' I hope I never see you again. I don't know where I'll go or what I'll do, but anything is better than stayin' with you!" With one last blow, the chair broke into pieces, while Genma dropped to the floor unconscious. Not even bothering to change back, Ranma stripped Genma's pack of the little money they had left, grabbed her own pack, and ran off, never looking back.

As she ran across a cliff overlooking the valley, her grief was so great that she didn't even notice when she accidentally knocked a boy over the edge towards the cursed pools.


Two weeks later, Ranma was starting to get worried, wondering if he should've stayed with his father after all. He was lost in the Chinese wilderness and had long since run out of food from his pack, forcing him to survive on whatever he could scavenge. The only piece of good news was that he had located a hot spring the night before, allowing him to change back into a boy for the first time since the incident. He had so far managed to avoid any cold water today, but he wasn't sure how long that would last.

His luck was still with him when he noticed a pile of fruit on the ground. Too hungry to realize or care that it must belong to someone, he sat down and began to eat.

He had almost finished off the entire pile when he heard angry shouts in a language he didn't understand. A boy and a girl about his own age were running towards him with angry looks on their faces. The boy had long black hair; was wearing a long, flowing white robe; had a pair of glasses perched on his forehead; and was carrying an armful of the same kinds of fruit as had been in the pile. The girl had long indigo hair, was wearing some kind of Chinese style blouse and pants, and was carrying a pair of weapons that resembled an oversized pair of maracas.

The boy dropped the fruit he was carrying, pulled out a pair of knives from the sleeve of his robes, and attempted to throw them. His aim, however, was terrible, and they landed well short of the intended target. Ranma then stared in disbelief as the boy attempted to charge him but instead ran into the trunk of a nearby tree, knocking himself out. The girl shook her head at the incompetence of her companion and charged at Ranma herself. She was an excellent fighter for her age but still no match for the boy who had been trained by the abusive methods of Genma Saotome. Before long, the girl had been disarmed and was on her back looking up in shock at him.

This exertion had been too much for the weakened Ranma, though, and he collapsed to the ground. However, he was still conscious, so he desperately tried to explain why he had done what he had done.

When Shampoo had escorted Mousse back to their fruit pile and discovered the young thief, she had assumed that she could easily defeat him. After all, he was only a single lowly male just as young as she was, while she was the best fighter of her age group and had aspirations of one day becoming the village champion.

Of course, stupid Mousse was no help as usual and had actually taken himself out of the fight. She didn't want him getting in the way, anyway. However, to her great surprise, she had been completely outmatched, unable to even touch the thief. Lying on the ground looking up in fear at the mere boy who had so easily defeated and humiliated her, she thanked the gods when her opponent collapsed to the ground. If she killed him now, there would be no witnesses to what had occurred, and she would be in the clear.

As young as she was, she really didn't want to kill anybody, though. When she heard the boy softly speaking in what she recognized was Japanese, she decided to give him a chance. She didn't yet know the language, but Mousse was partially fluent enough to at least understand the gist of what he was saying. She would need to use him to translate. She hoped the boy wouldn't reveal the true victor of their fight, but it was something she could live with. If she were forced to one day marry this outsider boy, and least he was good looking and a strong martial artist.

She was in luck as the boy didn't mention the fight but explained how he was lost, hungry, and all alone. The two amazon youths took pity on him and carried him and his pack back to their village. Shampoo took him to the woman she respected most, her great-grandmother Elder Cologne, who among other qualifications spoke fluent Japanese.

Ranma told Cologne his life story and explained about his curse, although he asked for and received a promise from her that she wouldn't tell anyone about his curse unless absolutely necessary. Cologne gave Ranma a brief explanation of their village and explained that as a society with a strong emphasis on family and children, they could never turn their backs on him. She arranged passage for him back to his original home of Tokyo, Japan (Ranma couldn't remember any more than that) through the Chinese Embassy, whereupon the Japanese authorities would be able to take care of him from there.

For the next few days, Shampoo nursed him back to health and had a few conversations with him through her great-grandmother. Ranma greatly intrigued her, and it wasn't long before she made up her mind. The night before his departure, she snuck into his room and kissed him on his lips while he was sleeping. Once he was gone, she would tell her great-grandmother the full truth and promise that she would one day track him down.


Once Ranma arrived back in Japan, he was escorted to the police station in the Minato Ward of Tokyo. One of the desk officers on duty looked through the case files that had been prepared on both Ranma and Genma Saotome. He was about to call Child Services to take the young boy when he noticed something in Genma's file. He was still married to a living woman named Nodoka Saotome. As Ranma himself had known nothing of his mother and had assumed she was dead, this Nodoka was probably just a step-mother who Ranma had never known. Still, as long as she was capable of caring for a child (not an easy assumption for any woman who had married Genma Saotome after what he had read about the man), Child Services may not be needed after all.

Just in case, the desk officer then accessed the birth record of Ranma Saotome and was surprised to discover that Nodoka Saotome actually was the boy's biological mother. He did a quick check to make sure this was the same Nodoka Saotome who was still married to Genma and found that she was. Even better, she still lived right here in Tokyo, in the Nerima Ward. As long as she was judged fit, Ranma could just go home with his own mother. The poor boy couldn't have asked for anything better, although his opinion of Genma Saotome dropped even lower upon the realization that he had purposefully kept this information from his own son. He quickly authorized a background check on Nodoka Saotome and made his call to Child Services to explain the case and what he had learned. When he was done with that call, he looked up another number and made another call…


Nodoka Saotome was doing some housework when she received a phone call that would change her life.

"Hello, is this Nodoka Saotome, the wife of Genma Saotome and the mother of Ranma Saotome?"

"Yes, it is," Nodoka responded curiously.

"This is Officer Suzuki of the Minato Police Department. If you're currently standing up, I suggest you sit down."

This was something nobody ever wanted to hear from a police officer after referencing the names of her family members. Nodoka took a seat, panic rising in her chest. "Okay, I'm sitting."

The officer continued, "Mrs. Saotome, when was the last time you saw your husband and son?"

Now fearing the worse, Nodoka gulped and answered, "My husband took my son on an extended martial arts training trip about four years ago. He sends me letters about their travels every now and then. Did something happen to them? Please tell me they're alright."

Officer Suzuki silently cursed to himself at how poorly he had handled the beginning of this conversation. "Your son is safe, but I'm afraid a warrant has been issued for the arrest of your husband on the charges of child abuse and numerous petty thefts."

Nodoka's voice caught in her throat. The thievery didn't surprise her, as she had long known Genma to be somewhat less than honest when it came to money and food, but the news that he had abused Ranma, their only child, came as a shocking blow. She had thought that it would be alright to let them go when Genma had signed that contract, but she now realized she had made a horrible mistake in letting him take her son away from her as tears began to form in her eyes.

After a few seconds, she controlled herself enough to speak, "Where is Genma now?"

The officer replied, "We don't know. Ranma ran away from him in China a few weeks ago and hasn't seen him since. Ranma luckily found some sympathetic people who arranged for him to come home to Japan. He's currently here at the station if you would like to see him."

"There is nothing else I would rather do more right now," said Nodoka. "I'll be there as soon as I can."


Nodoka took the subway to the Minato Ward and soon arrived at the police station. She gave her name to the officer at the front desk and was told to take a seat. A minute later, an officer approached her and introduced himself as the officer to whom she had spoken on the phone. He explained that before she could see Ranma, she needed to agree to a DNA test (Ranma's DNA having already been taken from a cup of tea he had been given to drink) to prove their relation, as she hadn't seen her son in four years, while Ranma had no memories of her and didn't even know she was alive (Nodoka winced at this news). She agreed, and a few hours later she was finally taken to see her son.

When Ranma had arrived at the police station, he had been taken to a private room and given clean clothes and several things to eat and drink, although he had been careful to only ask for hot tea as his beverage of choice. Before long, detectives had arrived and politely questioned him for details of his life with his father. He held back everything about Jusenkyo and their curses, instead blaming the Cat Fist training as the event that had caused him to run away.

Afterwards, he had become bored just waiting around, wondering why they were just leaving him here. He wondered what they would do with him now that he no longer had his father around. Every once in a while, one of the officers would come in to talk with him, but he couldn't understand why he was still here.

Eventually, one of the officers returned, but this time he was escorting a woman with auburn hair in a kimono who was carrying a cloth-wrapped bundle. When she saw him, she began to weep. Ranma supposed that this woman had been asked to take care of him until they found a permanent place for him, but he couldn't understand why she would get so emotional just at the sight of him. Sure, he had expected that his situation would get him a lot of pity (although he really didn't want a whole lot of it), but this was way over the top. Seeing his confusion, the officer stepped forward and explained, "Ranma, this is Nodoka Saotome, your mother." Ranma's jaw dropped. Quietly, he asked, "I have a mother?" "Yes, and she's here to take you home with her," the officer announced with a smile. For the second time in his memory, Ranma began to cry. "Mom!" Mother and son ran at each other and embraced each other fondly.


Nodoka's background check came back clean, and after a few visits the social workers concluded that Nodoka was a fit mother, giving her full custody of Ranma. Ranma told his mother everything, including about Jusenkyo and his curse. When he first demonstrated it, Nodoka had been shocked and began thinking about the contract with her husband. However, it didn't long for her to conclude that she couldn't count such a thing against him, and she had already noticed that he had turned out better than she had expected after what he had been through. Besides, it was now her job to finish raising him to be a "man among men."


A couple of months later, Genma managed to track Ranma down and showed up at their door one day. Ranma hid in his room, while Genma told his wife to "fetch that ungrateful boy who ran out on [him]." Genma never saw it coming. He was soon unconscious on the ground with a long bruise across his chest. Ranma saw this from his window and came down to learn that the katana his mother carried was actually a reverse-blade sword handed down from her great-grandfather.

The police showed up and arrested Genma. Eventually, his case went to trial, and Ranma gathered the courage to testify against him, although he once again avoided any mention of Jusenkyo, and Genma wisely avoided the subject as well. The most d***ing piece of evidence was a recording of a demonstration of Ranma in the Cat Fist in a controlled environment that the police had set up that Ranma had agreed to undertake. By this point, Ranma had grown close enough to his mother for her to be able to safely bring him out of it. Genma was sentenced to two years in prison, during which time Nodoka divorced him and once again became Nodoka Himura.

Over time, Nodoka did her best to raise Ranma on her own, taking it upon herself to improve Ranma's social skills and free him of some of Genma's attitudes that had taken hold over the years. Although she too wanted nothing more than to see Ranma grow up to be a "man among men," and an outside observer would certainly question some of her thoughts on manliness, she did teach him that women are not weak but should still be shown proper respect, and it's okay for a man to express his feelings and even cry from time to time.

She could tell, though, that Ranma's first love was still martial arts and that he was disappointed that he had nobody anywhere near his level with whom to train. Once Genma was released from prison, she and Ranma arranged a compromise with him and the police. On the weekends, Genma would be allowed to visit and train Ranma within her supervision and while wearing an ankle bracelet. Any other time, his restraining order would remain in effect.


School proved to be an interesting challenge. Genma had at least arranged for Ranma to attend school whenever they stayed in the same place for a few months, which was enough for him to pass the test to allow him to be in the right grade for his age group. However, as young as Ranma still was and with how vicious Nodoka knew other kids could be, she knew school would be miserable for him once his curse was revealed. To solve this problem, Nodoka arranged for Ranma to attend elementary school in another part of town and registered him as a girl named Ranko Saotome with the help of some sympathetic members of the school board, who also explained to the teachers why they could no longer bring hot drinks to work. With this precaution, it would be nearly impossible for "Ranko" to encounter hot water at school, although she always had a water bottle in her school bag just in case. Ranma wasn't happy about pretending to be a girl at school, but he knew the alternative was even worse.

"Ranko" was definitely a loner at school. At their age, the boys would mostly ignore the girls, and Ranko herself felt uncomfortable befriending any of the girls. Besides, she felt she couldn't afford to get too close to anyone with her curse.


When Ranma was 12 and 6th grade came along, he found that things had changed in school for Ranko. By this point, his girl form had already developed a significant bust and was also well on its way to otherwise developing a very feminine figure, to the jealousy of most of the other girls in her grade. Of course, by this time, most of the boys her age had discovered girls, and the combination of her mature figure for her age with her striking red hair and naturally attractive face led to the consensus that she was the prettiest girl in the school. Ranko would silently curse Jusenkyo for giving her such a body whenever one of the boys would attempt to come on to her. No amount of time in front of the bathroom mirror at home was worth this. Of course, these attempts would always end in failure where the boy was concerned. If it weren't for the fact that Ranko mostly avoided socializing with everybody, rumors would've certainly spread that Ranko was a lesbian.

Ranko's developing figure also led to other changes in Ranma's life. For one thing, she was now forced to wear bras to school. It also took a little getting used to adjusting how he walked and ran between his two forms now that his female form had wider hips. As an extension to that, he now had to practice his martial arts in both forms to make sure he could move correctly both ways. Luckily, having his father back as a sparring partner later that year kept him from falling too out of practice.


The biggest event of the school year was the school play, which turned out to be "Romeo and Juliet." Somehow, the 6th grade boys basically forced Ranko into the role of Juliet, claiming that the role should naturally go to the prettiest girl in school. Eventually, Ranko agreed to take on the part, aware that they had no way of knowing that in her heart she really wanted to play Romeo as a guy.

For this reason, he felt quite a bit of sympathy for the one who would actually be playing the role of Romeo. Like with Ranko, Romeo's role had been practically forced upon this classmate, who was actually a girl herself, although unlike Ranko's situation at least everyone was aware that she was actually a girl playing the role of a boy. She had short dark blue hair and was known as the best athlete and martial artist in school, rumored to even be good enough to defeat adult black belts. Ranko highly doubted this city girl could beat her after all she had been through even with being out of practice for the last two and a half years, but it was still very impressive.

Ranko had noticed this girl a few times before, but once rehearsals began, she got to know her a lot better. Even though there would be no actual kissing (Ranko would've never accepted the role if there was), there was still a lot of one-on-one rehearsal time required between the two leads. Ranko discovered that she was the most spirited girl she had ever met, and her smile could light up a room. Also, they both shared a true love of the Art, although Ranko still hadn't told anyone at school that she was a martial artist. By the time the play came around, Ranko had developed a huge crush on this girl, although it hurt that nothing could ever come of it due to her alias. The girl was also quite friendly and made several attempts to befriend Ranko, such as asking whether they could rehearse together at one of their houses. Ranko was highly tempted to accept these offers of friendship but forced herself to decline. If she allowed herself to become friends with the girl, it would hurt too much when she eventually learned of her curse and rejected her. Eventually, the play came and went as did the end of the school year. As time passed, Ranma forgot the name of this girl, but no one ever completely forgets about his/her first love.


Things changed as Ranma prepared to start junior high. He and his mother agreed that it would no longer work for him to attend school as a girl. He was now old enough to handle what the other kids thought of his curse, and it would be a lot better than having ever increasingly hormonal boys hitting on his girl form with its ever increasingly attractive figure. In fact, he had decided to just announce and demonstrate his curse on the first day to get it out of the way. He also felt that he needed to be himself in school after nearly three years of pretending to be a girl. Most importantly, junior high students were expected to change clothes and shower for gym class, something he could never accept doing with the girls even if nobody ever found out.

He therefore transferred over to the junior high nearest his house, with his school records secretly having the gender corrected thanks once again to some helpful people in high places. Throughout junior high, although it was a relief to be able to socialize normally with the other boys, many of whom were very respectable about his curse, he still mostly kept to himself, only allowing himself to be friends with his mother. He just knew that nobody else could truly accept him with his curse.


Of course, Nodoka couldn't help but worry about her son's lack of friends. It just wasn't right for him to go through life friendless and alone. She had tried to convince him that if he put some effort into it, he could find some true friends who would accept his curse, but he wasn't willing to listen.

Finally, Nodoka made a decision in the best interests of her son. He would be starting high school soon, and she couldn't let him drift like he had through junior high. Desperate times call for desperate measures, so it was time to take him to fulfill an old agreement her ex-husband had made with his best friend, Soun Tendo. Although it bugged her to be doing anything that idiot panda had arranged, she had no quarrel with Mr. Tendo and knew that he still expected the agreement to be fulfilled someday.

Nodoka made the arrangements for Ranma to be transferred to the same high school the Tendo daughters attended, Furinkan High School. The day before the school term was set to begin, Nodoka made the announcement to Ranma at breakfast. "Ranma, your father won't be coming over to train with you today. Instead, the two of us are going on a special trip. Your father has an old friend and former training partner named Soun Tendo." At the look on Ranma's face, Nodoka amended, "Don't worry. He's an honorable man unlike your father. Anyway, his family actually practices the sister branch to the Saotome Style in the School of Anything-Goes Martial Arts, and he owns a dojo here in Nerima. How would you like to go visit?" Ranma enthusiastically agreed, although Nodoka felt guilty that he wouldn't be very happy about it once he was told the true purpose of their "visit."

The day before, she had called Mr. Tendo to inform him that she had something important to discuss with him concerning his old friend Genma Saotome and to make sure his entire family was home today. However, she hadn't left her name nor provided any other details. She would privately discuss the situation with Soun once they arrived but felt it would be better for it to be a surprise for both Ranma and the Tendo daughters. Hopefully, once they spent some time together first, things would go over more smoothly once the bombshell was dropped.

A little while later, Ranma and his mother entered a cab that would take them to the Tendo compound and another turning point in Ranma's life…


Author's Notes: My goal in writing this story is to create a believable alternate universe following the manga arcs where Ranma's and Akane's relationship is allowed to develop as naturally as possible. In the manga, I see these as the major reasons why Ranma and Akane can't get along:

1. They got off on the wrong foot the day they met.

2. The extra fiancées and other suitors keep getting in the way.

3. They're afraid to get too close out of fear of their fathers pushing them into marriage, plus the whole idea of the arranged engagement in the first place.

4. Ranma keeps sticking his foot in his mouth, while Akane is too quick to jump to conclusions and lose her temper.

5. Due to the way he was raised, Ranma has trouble showing his emotions, he has trouble respecting Akane as a martial artist, and he has trouble understanding how his insults hurt her.

Now, it just wouldn't be Ranma ½ without #1, #2, or the arranged engagement (although #1 will occur quite differently this time). However, if I could get Genma mostly out of the way to eliminate #5 and help with #3, which would then lead to drastically reducing #4, it could work. This is what I came up with to go about doing so.

Anyway, I probably won't update this one very often, and it could take years to finish, but I eventually want to go through the whole manga, although I'll be skipping some minor arcs that I don't like or no longer make sense in this AU. For example, you may have noticed that Ranma didn't encounter the Dragon's Whisker this time, so that entire arc will be skipped.

Before anyone asks, yes, this Ranma isn't as good at martial arts as the one at the beginning of the actual manga due to his disrupted training. However, he's still more than a match for Kuno, so it won't matter until Ryoga shows up (and yes, I know I'm stretching it with how I adjusted the timeline concerning Ryoga, but there was no other way to get his story to work within the bounds of this AU). Eventually, Ranma will have all the training he needs to catch up to where he was in the manga.

Yes, I admit that I stole the Rurouni Kenshin connection from "Ranma, the Second Time Around." However, it just makes too much sense not to use despite the fact that Nodoka is shown not really knowing how to handle her sword in the manga. As that author says, the red hair has to come from somewhere.

Okay, the police department probably doesn't have all that information available at their fingertips, but it would've slowed down the pace of the story too much to be any more realistic about it.