A/N: I have had this headcanon that Ken is aiming to be a prosecutor for a while. Now this happened.

This is P3 cast in the P3xAce Attorney universe. It is 2016 in the Persona universe, which is the year that the first game of Ace Attorney takes place.

No, I don't have any plans or how this is supposed to continue. It's just a little world building piece.

Warning: it's very silly full of plot holes

There was a loud bang of the gavel. "Court is now in session for the trial of Junpei Iori."

"I know nothing!" Junpei shouted from the defendant's chair.

'Please act like you actually are twenty four,' Ken thought. Of course he wouldn't say that out loud. He had to keep the air of professionalism. "The prosecution is ready, Your Honor."

"The defense is ready, Your Honor," a black haired man said. That yellow scarf and dopey grin. There was only one Ryoji with slick back hair and two horns sticking out like that. Beside Ryoji was a blue haired man with an mp3 player around his neck. Minato was here as Ryoji's supervisor. Good, another person who was an adult and actually acted like one.

The judge nodded. "Your opening statement please, Ken-kun."

"Thank you, Your Honor..." Ken internally groaned for the honorific. He had turned eighteen just recently. He's an adult too. "One Kirijo Electronics' android was found destroyed in the back alley. From the damage, the android must have been beaten with a baseball bat at the scene of the crime. The baseball bat was covered in the defendant's fingerprints. That is the reason Junpei-san was arrested."

"... And?" The judge prompted.

"That is all, Your Honor," Ken said.

"And, and what about his motive?"

"Unknown." Ken frowned. "Junpei-san has refused his relation to the crime."

"I didn't do it!"

The judge ignored Junpei. "Is there at least a witness?"

"There is one." Ken sighed. "The prosecution considers him unreliable. However, there are no other leads otherwise aside from the murder weapon."

"What do you mean?" Ryoji tilted his head. "He's clearly guilty. isn't he?"

"You're my defense attorney!" Junpei shouted.

"I have to disagree, Ryoji-san," Ken crossed his arms. "The evidence is far too weak and the witness seems to come out of nowhere. I have no idea why I have to prosecute this case."

"Because…" Ryoji snapped his fingers. "Guilty until proven innocent, right?"

"Innocent until proven guilty," Minato said. "You need to trust your client more."

Ryoji pouted. "But, but his fingerprints…"

"Anyway," Ken said. "In my eyes, Junpei-san is still innocent. We can't hand him the verdict without hearing what the witness has to say."

"I didn't even go near the alley!" Junpei shouted. "No one listened to me!" He turned to look at the prosecutor's bench. "Hey, Ken! Won't Aigis be here?"

"She will be," Ken said.

"And she will prove you innocent," Minato said.

"But we might as well listen to the witness in the meantime," the judge said. "The prosecution may call its first witness."

A blue haired weirdo in a green tracksuit came up to the witness stand. The way he pushed his glasses up suggested he's a real jerk.

"Witness, state your name and profession," Ken said.

"Jin Shirato, just a passerby," he said and adjusted his glasses again.

"This is what I meant by 'coming out of nowhere'..." Ken muttered. 'I don't even understand why they arrested you in the first place…'

- The testimony -

I was walking passed the back alley… that's when I saw that guy with the cap!

That guy swung the bat and hit that robot's head.

Then there was a gunshot and that guy ran away, dropping the bat at the crime scene.

...

"Did I miss something?" Ryoji scratched his head. "Why would there be a gun?"

Ken frowned. "There is no gun wounds, gun holes, or any guns in the area."

"But I heard!" Jin said.

"They don't exist," Ken said. "You must be illusional."

"I'm not!" Jin banged the table.

"Maybe there was something loud?" Junpei shrugged. "You sure you didn't like, take drugs?"

"No!"

"Whoa dude, no need to be aggressive."

"So uh," Ryoji spoke up. "You saw Junpei used the baseball bat. Since it's our decisive evidence so I'm making sure, where does it come from again?"

"It was lying on the floor of the crime scene," Ken said.

"I dunno how it ended up there! I must've dropped it!" Junpei said from the defendant box.

"The bat is covered with Junpei's fingerprints right?" Ryoji asked.

"Because it was mine, of course!"

"It's yours," Ryoji said. "And the damage on the android matched the weapon."

"We are confident it is the murder weapon," Ken said.

"I lost that bat!" Junpei said. "I don't even know where it was until now."

Before the judge could hit the gavel to make people quiet down, the door was opened.

A blonde haired girl was at the door. "I have arrived."

Junpei's eyes lit up. "Aigis!"

"I am here." Aigis held a box up. "And I will prove Junpei innocent."

"What is that?" The judge asked.

"The victim's memory." Aigis handed the box to the bailiff. "It contains the clear face of the true culprit. You could call it camera footage, just that the camera happened to be the android's eyes."

"What?" Jin's face paled. "Why would Ik-"

Aigis replaced Jin on the stand. "I am Aigis, detective of police. I am here to present decisive evidence which has been approved by the chief of police. This evidence came from the victim's body and is therefore related to the crime."

The whole courtroom was silent as the video showed Jin hitting the viewer, the android, and then Jin was clearly running away before he could get the android memory system. The video file was without sound, but even with just the visual, it was clear who the killer was.

Jin was arrested and Junpei was declared not guilty

...

"... What the heck," Ken said when they were all at the defense lobby.

"Indeed," Aigis said. "The case is simple enough that if they investigated the crime scene more thoroughly, the true culprit would have been arrested."

"Really weird huh?" Ryoji said.

Junpei glared at Ryoji. "Who was it that said my fingerprints on the baseball bat was decisive?"

"Ehh." Ryoji shrugged. "Anyway, why would the police arrest so quick? Aigis just got the right evidence in the end."

"I admit I have faced some difficulties before arriving here." Aigis looked at the prosecutor. "Ken, I have my suspicions…"

"I know." Ken had the same doubt as Aigis.

Minato nodded, and everyone seemed to have forgotten he was also there.

"The police must have made a rash arrest. Someone in the police wants to pin it on Junpei to avert the attention from Jin."

Ken continued, "But since I was unwilling to let Junpei-san be declared guilty with only one piece of evidence, they decided Jin had to testify."

"By the way, that guy seemed really paranoid in the video." Ryoji rubbed his chin. "What was Jin trying to salvage from that dumpster?"

"I have checked the area," Aigis said. "Jin was going to check the hidden place for drugs."

"... The police are involved with drugs dealing," Minato said. "Is that what you two are suspecting?"

"Correct." Aigis nodded. "There is more to this. Perhaps Mitsuru-san and Akihiko-san would want to be notified of this case."

"The Arisato Law Offices is always willing to help," Minato said. Ryoji grumbled in the background.

"Ace detective Junpei doesn't want anything more than to get his baseball bat back," Junpei said.

...

Ken went back to his house that evening. Koromaru was running around the living room. The TV was playing Featherman R Phoenix Ranger rerun. Aigis was carrying the laundry to the guest room. Ken grimaced. "Don't tell me…"

"Akihiko-san will take the guest room. He will arrive tomorrow morning."

"Ah… okay." Ken sighed in relief. Mitsuru wasn't coming too. "By the way… Aigis, you didn't play the gunshot sound to make Jin ran away, did you?"

"I may have," Aigis said. "I could also play the voice clip that says 'you are under arrest' in more than thirty languages."

"I'm just glad you didn't use your real guns…" Ken later forgot all about the case as he watched Featherman R with Aigis and went to sleep.

His phone later got a message that said, "Très Bien, Amada."