A/N: Okay, so since I lost my muse for this story. I'll just be summing up what's going to happen next. Sorry about that and thanks for holding on(?)
When Rin and the rest would arrive at the place, they'd get two surprises; Bon's mother and then Rui dressed up as a Maiko (apprentice geisha). Bon's family is a subsidiary of the Nise Family ever since the Blue Night happened. Rin and Izumi would be happy in being reunited with her again and so does everyone else, who by now has learned about her status as an angel. She's there to help out but mostly to see Izumo and Rin again because she's been lonely.
They chat and she makes Rin feel better.
The rest of the arc continues as the canon except Rin isn't as down as when Shiemi declares their friends forever status. And the last day ends up as a group outing and a date with Rui who receives a Kikyo hana kanzashi from Rin who learns from Mayu that Rui was born on the 8th of September. Rui gets left behind in Kyoto because things with her family aren't fixed yet but she leaves Rin a promise that they'd be meeting again in Tokyo and gives him a token.
Later on Shura teases Rin about this because it almost seemed like Rin was buying her freedom. Which Rin denies while blushing because he knew Rui would get out on her own will and he'd help but she'd probably do most of it by herself. Shura smiles at Rin's acknowledgement of Rui's own strength. Back at the Nise Mansion, Rui's seating formally and facing her Mother, the current stand-in head for their family, and a very stoic Raziel. The negotiation about her return to exorcist academy ensues, her Mother questions her gently about why she left so suddenly and Rui answers about finding a B class exorcist.
Raziel gets mad and starts a shouting match by insulting the exorcist Rui's finding. She screams back and it almost comes down to a fight but both are surprised when they are forcefully made to kneel by a furious looking Mother. Raziel looks ashamed while Rui looks down, Mother gently scolds Raziel and shows her support for Rui going back to True Cross to search for the exorcist that helped them long ago. Overjoyed Rui unconsciously breaks through the binding spell her Mother casts and shocks everyone in the room while she hugs and sobs at her Mother's arm, unaware of it. When Rui leaves the room to pack her things, Her Mother's demeanor changes and coldly addresses Raziel by his human name, informing him that Heaven still hasn't claimed her daughter's soul and so he had no right to do what he did back at the Training Camp.
Obviously frightened, Raziel apologizes but comments that Rui was necessary if Heaven ever decides that Satan was overstepping his bounds and coldly reminds Mother the deal that their ancestor had made to exist and to never forget the meaning behind 'Nise' before disappearing in a flash and leaving a single white feather.
Rui and Rin reunite at the beach where she greets him in her two piece swimsuit and Rin realizes that Rui had a curvaceous body, something he never really noticed when he dressed her and Izumo pouts at the realization that Rui had been wearing chest binds. The kraken arc happens like in canon with the exception of Rin and Rui's romantic tension building up and Rui realizing something's not quite right with Yukio. She confronts him on this once the other exorcist starts making Yakisoba.
Yukio acknowledges her suspicions that he's jealous of Rin. Rui accepts this and says she understands and hints at the fact that she used to have an older sister, Yukio is surprised by this admission and Rui merely says that if she was able to surpass her older sister Yukio could do so and assures him nothing bad would happen because his situation is less complicated than hers.
A flashback happens during their stay in Kyoto where Rui and Rin are left behind while everyone else goes to a concert. Rui and Rin are in a private room and the lights are dimmed, Rui's holding a shamisen and playing for Rin who looks amazed because Rui really looks beautiful. They end up moongazing and they share their lonely childhood with each other, it ends with Rin saying a cheesy line about the moon and Rui laughs at this before agreeing with him echoing his words back. Causing Rin's heart to skip a beat and then it comes to Rin asking about her injured wings and Rui shows him that her wings are fine before she asks about his flames.
Rin shows her his demon form and he happily pets his tail that wraps around her wrist softly and then touches his horns before commenting that his flames remind her of someone who was like him.
Rin is surprised by this and blushed when Rui comments that his flame are just as warm as her exorcist.
They spend the rest of the night like that until everyone returns to the inn. Rin doesn't forget the soft brushes his tail does against Rui's white wings and realizes that his skin doesn't burn even though he was touching Rui. He wonders about this for a moment before completely ignoring it.
The flashback ends and shows that Rui has returned and uses the excuse of family emergency, everyone notices the knew found attraction between Rin and Rui, with Rin being gentle towards her and Rui's surprising feminine attitude and gentle smile. Izumo and Paku supports them though Izumo is more reluctant, Rin and Rui remain oblivious about their attraction to each other and steadily insist that they're just friends though even Yukio has commented that they act like a newlywed couple back at the dorm. And Rin's been inside Rui's room and Yukio drops that he had never been even allowed in her room's floor. Rui diverts the attention to Seven school mysteries successfully and the rest happens just like in canon but Rui gets told that she should learn to be more honest with them and she thanks Konekomaru for it.
But her mind echoes back what it means to be a Nise.
The chapter ends just like in canon. Mephisto rambles about desires and shows both Yukio and Rui as two people driven by the desire for knowledge. It cuts back to Yukio making small talk to a tired Rin and mentioning a meet up with Shiemi and shows his support for his younger brother. Yukio is surprised by this before remembering Rui and the scene cuts into Yukio teaching Shiemi as his mind flashes back to the past about unanswered questions and the Nise family's involvement in this. Mephisto laughs at Yukio's predicament and turns his attention to a Rui who is spending time with Rin in the dorm lounge, Mephisto comments on the irony of a Satan's son falling for the same person twice and says that Rin was more human than demon when around the damned angel.
Amaimon interrupts with a blaise comment that humans die anyways and Mephisto apologizes for this and admits that he too was searching for what "lies ahead" that evaded him before saying good bye from the other plane.
The scene cuts back to the school festival that everyone is preparing for. Izumo, Rui and Paku's class are doing a cafe and all the girls are excitedly talking about the dance party and the Izumo and Paku ask whether Rui planned to go with Rin and she answers about not being sure before Rin excitedly calls out for her and she greets him and Godaiin. Rin asks her out for the Dance party and then sets Godaiin up with Paku. Izumo merely sighs before reminding Rui about her missed lessons and the qualifying exams and Rui comments she hasn't been slacking off and thanks Izumo. Rin announces it as a date which everyone in the classroom hears before rushing off with Godaiin. Rui blushes deeply because this is her first time, this becomes the talk of their year. Everyone is then surprised by Shiemi being accepted midyear, Shima rejoices at his chance to attend and everyone else congratulates them. Rui and Rin have an eye contact and looks away from each other blushing.
Konekomaru comments that this soft Rui is a nice sight despite being something to get used at as they were used to her slightly cold demeanor. Shiima comments that Rui's popularity has skyrocketed since getting together with Rin.
The rest of the school festival arc happens just like in canon but Rin confesses to Rui and Rui agrees to them going into a one month trial dating. News of them dating spread quickly as Rui musters to tell Rin the reason why she came to True Cross. They go to several in school dates and dorm dates while falling for each other, Rin accepts that Rui might not fall for him back with her being an angel while Rui worries that she might be projecting her exorcist to Rin. In one of their dorm dates after leaving the dishes to be cleaned by ukobach they head to the roof and star gaze. Rui comes out to Rin about her true purpose and tells him about the exorcist from her childhood and Rin silently accepts that he was just a stand in and tells Rui that it was better than her not being able to love him because of being Satan's son but Rui denies this, suddenly sitting up in anger and says that she has fallen for Rin not because she sees him as a stand in but because she's finally seeing Rin for Rin.
She tells him the reason why Amaimon easily got her was because of her not seeing him properly, and now that she finally does she's free from that guilt and Rin kisses her on the lips and she returns it. It's clumsy and both laugh at their first kiss and Rui promises to be his angel and be with him until he becomes the Paladin. Rin promises to defeat Satan and then announces his intent to be with Rui for a long time (a marriage proposal) which Rui accepts and she hugs him along with her white wings as Rin's tail curls around her protectively.
Rin thinks about how safe and warm it feels trapped by Rui's wings and then kissed her cheeks softly and tries for another kiss on the mouth this time it's better than the first.
The rest of the Illuminati arc happens just like in canon with the exception of Lucifer hinting that there's more to the Nise Family than the Order knows and asks Rin, "what did you do to look younger again, dear brother?"
Which confuses everyone but Rui who realizes that Samael may have something to do with the exorcist whose pendant she has. Rui immediately realizes that the exorcist from her past might have been a Rin Okumura from the future who was probably going to prevent something but Rui discards this thought as she feels that she would immediately know if Rin was acting weird. Shima goes missing and Izumo reunites with her family all the while with her realizing she's starting to fall for Rin and becomes guilty of this, Rui however has her attention in finding everything about what happened on the day the exorcist from her past came to help her.
Rin catches upon Rui's sudden change and asks her about it. Rui hesitates before telling him the truth, Rin offers to accompany her and the two sneak out of True Cross academy via the Yokai world. She says that Rin would have no problem blending but her holy aura was hard to conceal Rin solves this by dousing her with blue flames and the two while wearing casual clothes goes through the Yokai world and stumbles upon Nora-no-kami, The goddess for those without homes, who offers to open a portal for them to the main estate of the Nise family in exchange for getting her peach beads. The two successfully completes this quest with the help of yokais under contract with Rui who congratulates her for finding a good danna-sama (Husband/Master). Rui blushes and Rin thanks them for this.
They arrive and are greeted by the family's main guardian, a dragon that has been watching over Rui for a long time. Ryuu no Ou leads them to family shrine hidden deep in the Nise estate and reveals Rui's suspicion as well as the fact that it was indeed an Okumura Rin from a future but non-existent universe who came to help her in the past.
Rin questions this and Ryuu no Ou answers that only the his other self could answer this. He gives them a clue meanwhile back on True Cross, their disappearance is noted when the shikigami Rui used to act as clones are dispelled, all True Cross branches are informed and the Vatican orders a search for them. The Nise family is noted just in time as they are informed of intruders, a woman wearing a black kimono orders them to capture the intruders. The head maid replies whether and addresses her as Maria-sama, and welcomes her back from her exile. Ryuu no Ou then says that Maria has returned and cautions them to avoid a battle with her as Maria has grown stronger than Rui and wishes to separate her from Rin. Rin thanks Ryuu no Ou before taking Rui and fleeing.
They decide to run to Aomori as Rui remembers the older Rin mentioning something important happening there. They head to Aomori via the yokai world and gets help through a Yuki Onna who Rui knew. Arriving at Aomori, Rui uses a shikigami to buy them hair dyes and the change their hair colors, Rin to light blonde and Rui to medium brown. They pretend to be a married couple and buys rings to support this. Rin comments on her ability to plan and Rui stammers that she learned this out of manga, Rin laughs before kissing her. They rent a cheap room and stammers when they have to sleep in one bed. Rin asks about the older him and Rui complies before saying that it must have been fate.
Rin blushes and kisses her deeply, they're still out of practice and both of them go to sleep huddle against each other. They start asking for Rin's older self by saying they're looking for Rin's older brother. It takes them three days but they are led to a house on the outskirts and the two upon arriving are greeted by an older Kuro and Rin, who upon seeing Rui hugs her tightly. Rin feels slightly jealous but controls it, they come inside and directly tells him that they are looking for answers.
Older Rin complies but only after he has served them sweets. Then he proceeds to tell them the reason why he travelled back to the past with no way to go back. He starts with meeting a 16 year old Rui who acted was the head of the Nise Family, he meets her just after Illuminati incident as solving her case would be his exam. He tells them it was love at first sight and it was the first time he used his head, Rui laughs at this and Rin looks at her with a fond albeit sad smile, before he continues his story with the fact that the Rui of that time only smiled slightly and fakely. He says that his Rui was a very sad person whose only living family was her caretaker that got possessed by a demon. Older Rin then says that he ended up watching over his Rui while she slept to kill the demon, he laughs as he says that the reason why Rui was able to step out was because he had accidentally seen her naked. Rui asks about why still did it though if she got saved.
Older Rin replies,
"At that time, you were already taking poison that would slowly kill you...You died on our fifth year of marriage."
Rui is shaken by this and Rin comforts her. Older Rin offers them the guest room and Rin takes Rui there once Rui has calmed down and gone to sleep. Rin goes back to the living room and tells his older self to tell him the truth. Older Rin smiles wryly and offers him sake, Rin takes it and sits down across him under the kotatsu.
Older Rin then tells him the truth, He came back to prevent Rui from taking on the poison and killing off the demon that would have hurt her. Rin questions what this mean for him now, Older Rin answers that with them running away, the best way to prove his worth as a weapon for the Vatican was to fight off Rui's older sister who has been corrupted.
Rin wonders why such a person who cares for Rui would be threat. Older Rin says that in his future, Maria had helped with the destruction of both Assiah and Heaven because of Rui's death. Rin asks how the other Rui died,
Older Rin looks at his wedding ring and replies,"She died as an exorcist sent to a mission I wasn't told about. She had faced off one of our brothers and died with our two month old twins."
Older Rin then proceeds with warning him about trusting the Vatican, he tells him that the only one he could trust was his friends. He tells him that in the future Rui would be essential for the defeat of Satan. Rin asks if he was able to do it, his other self replies that he did but not without cost. He then tells Rin that now that he has seen Rui he's job is done and calls Kuro to take them away as the door is smashed to pieces and they are surrounded by servants from the Nise SP.
Older Rin releases his flames and tells Rin to take care of Rui and cherish her. Rin nods before making a path to retrieve Rui from the next room. They flee with older Kuro who drops them in the deep in the woods before returning back to Older Rin who has become heavenly injured. They flee and Kuro cries as Rin succumbs to his injuries and apologizes for taking Kuro with him who says it was fine because Rui and Shiro,Rui's cat, was waiting for them in the other side.
The two dies in the snow as they bleed out and both of them smiles. Older Rin is then greeted by a much older Rui who smiles and welcomes him back together with Shiro who has curled up with Kuro, Older Rin cries as he kisses her saying, "I'm back." Rui thanks him for everything he has done for her and the two then walks towards a gate that opens for them. This scene ends happily with the rest of their friends greeting Rin a welcome back.
The scene returns to Rui and Rin running deep into the woods and come across an abandoned cabin that feels familiar to Rin. He comes across a journal owned by a Yuri. Rui sets up alarms around the cabin 500 meters away to alert them, as Rin pages through the journal he realizes that they are where his mother met Satan. Rui comforts him as he realizes what the Vatican did, he grieves and Rui hugs him tight. They start a small fire as Rin contemplates whether he should be an exorcist, Rui pushes him on saying that if anyone could change the Vatican it could be Rin. He asks her where she gets this confidence, Rui replies that Rin's kindness is what makes her sure of it.
He thanks her and the two then begins making out with each other but it never gets past that. Rin says he'll do it once he's married to Rui and Rui accepts it saying it was something to look forward to. They both promise to make it out of here alive and to get married to each other. Nise with the promise of resolving her family's issue with heaven and Rin with his biological father.
Back in True Cross the rest of the gang focuses on the exorcist exam with their test being the capture of a runaway angel and demon. Everyone's mind immediately goes to Rin and Rui who they suspect has elope.
What happens next is basically a confrontation between the Vatican and Nise Family with the reappearance of Raziel who has come under orders from heaven to take her back for her trial. It's a four way battle between the Vatican, the Nise family, Raziel's small army, and Rin and Rui's group. It ends with a lot of casualties and the revelation with the meaning behind the name Nise which symbolizes their origin of not being a real. The first Nise was an angel that fell for a human and gave up his wings. Which explains the reason why the Nise Family produces one grigori soul per generation. It fight ends with a stalemate, Rin and Rui heavily injured.
When it seems that Rin is about to be killed, the skies light up and Uriel shows up with an order from Heaven, Rin was to be baptised and Rui to be sent to Sheol as her test to be part of Heaven. The Vatican is forced to accept as they are offered with the choice of being sent to damnation, Uriel takes Rui back after saying to Rin that the Triumvirate was watching over him. Rin wonders what this means as he sees Uriel hand his brother a two vials. Raziel and his army disappears along with Uriel in a flash of light, the fights end like that.
Flashforward with Rin 20 years later, he's already the Paladin and looking much older and more mature while remaining uncomfortable with his popularity alongside Yukio. When he enters his office, he is then greeted by his friend who comments that it was time. Rin smiles and his exorcist pendant catches the light and shows a simple cheap ring hanging next to it. Rin then rushes to the court yard just in time to hear a much older Rui grinning and flying towards him. They are reunited with and it ends with Rin and Rui professing their love for each other and kissing, on the side Shiemi is seen to be engage with Yukio, while Izumo asks Shiima when he plans to propose to her. Bon is dating Paku while Konekomaru was seeing a preschool teacher.
It ends with Rui being informed that Rin had the title Blue Exorcist.
Other facts:
-Rin and Izumo dated for a while before Rin ended with saying that he can't see it going any further. Izumo cries but accepts it.
-Shiemi and Bon dated before they broke it off mutually, his eventual relationship with Paku surprised everyone.
-It took a long while for Yukio and Shiemi to date and even then it was full of bumps as they are both insecure, Yukio about Rin and the brief stint Rin had with Shiemi, and Shiemi about how Rui's absence affects all of them. They work it out eventually and has agreed to be honest with each other about almost everything.
-Raziel and Rui was once arranged to be married but Raziel broke it off while in Heaven stating that he couldn't come between the two though he does jokingly reply that he doesn't mind waiting for when it doesn't work out. Which Rui comments that at least he's got that personality back.
-Rui comes back with three pairs of wings that Rin grooms for her which more often than not leads to sexy times. The main reason why Rui ends up giving birth to two children 9 months later and another one a year later.
-Their twins are named, Heika and Tennouji. Heika being a female carbon copy of Rin with dark skin inherited from Rui, and Tennouji a male carbon copy of Rui with pale skin. Their youngest child, Tenrai looks like a Rin with sharp eyes and medium brown skin.