Voice Actor: Johnny Yong Bosch (https://youtu.be/IM4VElABu4U)

Known as the Egocentric Police Dick. He's the main (later true secondary) antagonist in Persona 4,  

A police detective sent to work in Yasoinaba, and assistant to Yu Narukami's uncle, Ryotaro Dojima. While he initially seems like a goofy, clumsy buffoon, it is revealed that he is, in fact, the man behind Inaba's gruesome string of murders. Being sent to work out in a middle-of-nowhere town in spite of being the top of his class in the police academy, he became disillusioned by the way he perceived how the world had treated him. When he discovered his power to enter the TV World and send others in as well by accidentally pushing news reporter Mayumi Yamano in, he saw no problem in also forcing high school student Saki Konishi into the TV, knowing it would lead to her death, which lead Saki's lover, Yosuke Hanamura begin to join Yu's team. He even manipulated the ex-city council secretary Taro Namatame to throw the later victims into the TV for him under the impression that he was saving them from being murdered, thus continuing Adachi's "game". Despite being a murderer, Adachi is shown to have a limit when it comes to having involved little children into their doom like Ryotaro's niece, Nanako is not his style. After nearly a year of this, the Investigation Team discovered Adachi, chased him into the TV World, and brought the killer to justice, at which point Adachi accepted that he had lost the game. During a final battle against the Investigation Team where he was possessed by Ameno Sagiri, Adachi realize that he is not the only one who was toyed by his universe's Izanami (the same gas conductor he first met upon arriving at Inaba) into her scheme, Yu and Taro as well, thus warned Yu to end Izanami's schemes.

While spending time at jail, Adachi himself became a model prisoner. When Yu and his friends, alongside the previous Persona users within Shadow Operatives (formerly S.E.E.S.) all end up being the subjects to a Midnight Channel fighting tournament known as P-1 Grand Prix hosted by "General Teddie", for the culprit's deadly entertainments, Adachi was freed by the same culprits who started P-1 tournament, a young man with split personalities, Sho Minazuki, and “General Teddie” himself, into aiding them enacting their final plan to destroy all worlds with Shadows by announcing P-1 Climax, held in the real world under the second Dark Hour instead of TV World. Despite this, Adachi went undercover on secretly aiding Yu and his friends to stop the imposter Teddie’s destructively evil scheme, while also exploiting Sho is just like he was before, being an unwitting pawn to the deities of destruction.