How Adachi joined the Tourney
Throughout the story, Adachi is portrayed as a textbook lousy detective: he makes rookie mistakes, vomits at the sight of grisly murders and is seemingly unable to keep his mouth shut about the murder cases to anybody he speaks with, regardless of their involvement (or lack thereof) in the investigation. Throughout the story, Adachi gives the Investigation Team hints and updates regarding the murder cases' current status, which often influence the action the Investigation Team later takes.
As the Investigation Team saves more victims, Adachi, irritated that the Investigation Team is getting in the way of his "game," sends an anonymous letter to the Dojima residence threatening the protagonist's loved ones should he continue saving people. After Nanako is thrown into the TV, rescued by the protagonist and seemingly dies in the hospital, Adachi remains oddly collected. He points the group in the direction of Taro Namatame's room in the same hospital, and the group finds him attempting to escape the hospital.
After the Investigation Team rules out Namatame, they investigate further into the case and come up with bits of evidence and clues, central to this the threatening letter, and conclude that Adachi has strong evidence of being the murderer. After realizing this, the Team is informed that Namatame is going to have his transportation and rush to the hospital, where they trick Adachi into accidentally revealing his connection with the murder cases. In an act of desperation, Adachi runs away from them and enters the Midnight Channel as his final escape.
The Investigation Team tracks down Adachi, and find him within the very first area the protagonist, Yosuke and Chie ended up in: Mayumi Yamano's dungeon. Upon finding Adachi, the detective reveals that he held a romantic interest towards Mayumi Yamano and used his job on the police force to be alone with Mayumi while she stayed in the Amagi Inn, telling the others that he was sent by to protect her from the media. Curious about the affair, Adachi called Mayumi to the inn's lobby and asks whether her affair with Namatame was real, which Mayumi brushes off by saying she doesn't have to explain herself to him. Enraged that she didn't deny her affair, Adachi calls her "another worthless bitch" and pushes Mayumi back, accidentally dropping her into the TV behind them. Since Adachi only tried inserting parts of his body into the TV before, he was surprised and amused to see that humans can actually enter the TV. After the incident, Mayumi ended up as the first victim, with Saki Konishi acting as witness. Adachi later reveals he wanted to punish her for being a "stupid bitch" for "betraying" him, and never intended to fully push her in.
Adachi later questions Saki about her discovery of Mayumi's corpse. Through his questions, Adachi tries to seduce Saki, but Saki retaliates by slapping him. Spurned, Adachi pushes Saki into the TV inside the police station's interrogation room, being able to do so with ease since Saki's body was lighter and skinnier than Mayumi's. Boasting his accomplishment to the Investigation Team, Adachi remarks that he wasn't committing crimes, but merely establishing justice by killing those two "gold-diggers" hoping to swindle Namatame's money.
When Namatame realized that every victim that was murdered first appeared on TV, he contacted the police and Adachi was the one who answered Namatame's call. He gave Namatame the idea of pushing the people who appeared on TV into the Midnight Channel and mocks Namatame's efforts, wondering aloud whether he was caught up in a messiah complex. When a student named Mitsuo Kubo came to the police station to confess to the murders of Mayumi and Saki, Adachi's superiors were less than amused, and pawned Adachi off with the student. Since allowing Mitsuo to confess to the murders would effectively stop Namatame from continuing to kidnap the people appearing on TV, and Adachi couldn't bear to let his "game" of cat-and-mouse end so quickly, he formulated a plan to throw Mitsuo into the Midnight Channel. His plans were foiled by the Investigation Team, but because Adachi turned off the lights in the interrogation room Mitsuo had no idea that Adachi was the one who pushed him in.
When the Team finds him in the other world, Adachi comments that the "game" would be boring if the Investigation Team were unable to track him down, and mockingly congratulates them. The "Adachi" talking to the Investigation Team in Mayumi's reality was revealed to be an illusion, therefore Rise and Teddie later found out that Adachi was already in his reality, Magatsu Inaba. Adachi taunts the Team, and becomes surprised when they give in to his taunts. Adachi calls the Team "losers," and wonders aloud why wouldn't they take life simpler by just studying, growing up and getting through marriage. Adachi's ultimate goal was to create a large rift between the Midnight Channel and the real world, allowing the fog to completely engulf reality and making the world a place infested with shadows.
Upon reaching the final floor of Magatsu Inaba, Adachi sarcastically congratulates the team and confirms his murders. He proceeds to express his disgust and contempt towards the world and society and justifies his actions by saying that if all of humanity are turned into Shadows, they would be given an easy life of no worries or despair. The Investigation Team, however, refutes Adachi's words one by one, until Adachi's temper reaches its peak and he attacks them, revealing his own Persona, Magatsu-Izanagi.
After his defeat, Adachi is possessed by Ameno-sagiri, who was manipulating Adachi from within and was the real mastermind behind Adachi's plans of filling the world with fog. However, Adachi later expressed that it was also partially his true desire as well and he is still to blame for the murders. Upon Ameno-sagiri's defeat, Adachi questions the Team's reluctance to kill him, asking them if wasn't that their goal in pursuing him. The Team replies that killing him would essentially continue the cycle: one dies. Surprised by the Team's resolution, Adachi finally gives up and willingly follows the Team out the Midnight Channel.
Outside the Midnight Channel, upon the police's arrival, an exhausted Adachi is taken out on a stretcher, a personal favor from Dojima. Further surprised by this, Adachi finally acknowledges that despite Dojima's strict orders towards him, Dojima still cared for him as his partner. Guilt-ridden and touched, Adachi swore to confess his crimes to the police, making a full cooperation with them.
In the events of the True Ending, the Team receives a letter from the recently-convicted Adachi, stating his suspicions about there being a higher being orchestrating the entire thing. Unfortunately, he can only give vague clues at best; and tells the protagonist it is up to him to solve the mystery. It is revealed that his, the protagonist's and Namatame's ability to enter the Midnight Channel came from seemingly chance meetings with a Moel Gas Station Attendant the day they each arrived in Inaba.
Character Select Screen Animation
Lays back on a computer chair.
After the announcer calls his name
Raises himself and pulls his gun out as the camera zooms saying "Hey -- don't bore me, okay?"
Adachi shoots his pistol on the opponent's legs.
Adachi grabs his opponent, then a purple orb appears; From it, the Persona Magatsu-Izanagi. Adachi then pushes the opponent back as Magatsu-Izanagi sparks purple energy on the opponent.
Screw You! (Up)
Adachi does two jumping kicks then Magatsu-Izanagi swings its pike.
1. Calm Down/Pain in the Ass (Down)
Adachi walks suspiciously forward. If the command is done a second time, Adachi dashes to grab his opponent, and if he does, chucks his prey in the opposite direction hard.
Magatsu Mandala (Hyper Smash)
Adachi sighs then says "What a pain." as Magatsu-Izanagi makes a spiral of dark energy rapidly hitting opponents.
Yomi Drop (Final Smash)
Adachi clutches himself but then says "Here's a lesson for ya'!" then Magatsu-Izanagi sparks something to stun the opponent. If it does, the Persona drags the opponent to a monstrous dimension, while Adachi explains "You act high and mighty. But lose and you're just a loser!" The opponent is surrounded by wailing spirits as Magatsu Izanagi powers up then does a slash that puts the screen on the fritz and we hear a Star KO cry. A life from the opponent's stock lost, the screen returns to Adachi who says "Haha! Do you understand now?"
- Adachi turns his back saying "That was easier than I thought." while Magatsu-Izanagi sets its spear down. They then both disappear as a red mist covers the area.
- Adachi creaks his head then Magatsu-Izanagi sparks energy balls. Adachi then says "Too bad, looks like no A+ for you."
- Adachi shoots his gun saying "You're a bother." while Magatsu-Izanagi raises its spear.
Walks to his point and nearly trips then says "I hate looking after brats, you know?"
- Adachi's rival is a Presidential ninja candidate, Chipp Zanuff.
- Adachi's persona is Magatsu-Izanagi.
- Tohru Adachi shares his English voice actor with Zero, Emil Castagnier, Hammer Bro., Fire Bro., Ichigo Kurosaki, Zhang Bao, Yukimura Sanada, Jonathan Joestar, Cursya, Yagura, Kung Jin, Ryosuke Ishigami, Yang, Boomerang Bro., Poliwrath, Sasori, Yu Narukami, Masataka Takayanagi, Corrin A, Sledge Bro., Subaru Shinjo, Hayato Gokudera and Yukio Okumura.
- Tohru Adachi shares his Japanese voice actor with Richard Wong, Admiral Zhao, Klaa, Dimitri "Dima" Maykov, Kermit the Frog, Big Bird, Black Panther, Sorata Arisugawa, Rubber Soul, Constantine, Dubhe Alpha Siegfried, Sandslash, Mr. Reggie, Ernie, one of the adult Fossa, Larry the Cucumber, Wally Walrus, Yinglong, Burn Griffiths, Corsair, Kazemaru and The JoJolion incarnation of Josuke Higashikata. Mitsuaki Madono once did Noriaki Kakyoin in the Capcom CPS3 arcade game JoJo's Bizarre Adventure: Heritage for the Future.