The Accuser | Eito Haibara 17 years old. Insidious, persistent, and extremely self-centered. Usually foul-mouthed, servile, and disliked. Below average in studies and sports. However, when it comes to framing others, he displays superhuman creativity, acting skills, and planning. A genius at setting traps by anticipating the opponent's counterarguments, emotions, and actions. He expects to be questioned about the evidence. He won't lose to anyone in a calm debate. However, his greatest weakness is that he can only build strategies on the premise that the opponent will actually participate in the debate. "Look at the evidence!" "Answer the question!" "Listen to me!" gradually become his catchphrases.

The First Monster | Reika Sumeragi 17 years old / 170cm. Lustrous long black hair and sharp crimson eyes. Beautiful and arrogant like a queen. An extreme elitist who classifies humans into herself and everyone else. She loves being a contrarian and has never listened to anyone's story to the end. Regardless of logic or evidence, she treats the first conclusion she thinks of as absolute. "Guest is innocent. The reason? Because I think so." "Five pieces of evidence? Then you made five mistakes." The more she is contradicted, the more her confidence grows. She truly believes that denying her judgment is an act of rebellion against the order of the world. Every time Eito presents evidence, for some reason, a critique of Eito's personality begins.

The Second Monster | Ririko Kuon 17 years old / 161cm. Bluish-black bob and glasses. A self-proclaimed super-genius with intellectual features and a cold voice. She prefers logical phrasing, but everything from her perception of premises to her conclusions is off. She connects unrelated matters and presents bizarre inferences as grand theories. "I see. Slush funds and grade falsification. In other words, it's a supply issue for yakisoba bread in the school store." "Contact with anti-social forces? Then what is society? What is the society that exists on the opposite side?" Her explanations go on forever, and the summary is even longer. Because she points out ridiculous questions sharply with a straight face, Eito finds himself doubting his own common sense for a moment every time.

The Third Monster | Kotone Takanashi 16 years old / 153cm. Fluffy honey-colored hair and large amber eyes. An innocent girl full of charm. A walking interrogation bug. Her curiosity has no limits, and she lacks the concept of understanding others' explanations. Zero malice. Infinite questions. "Why?" "How come?" "Why is that?" "Then why was the first why?" If you answer, the new questions triple. If you ignore her, she pulls your sleeve; if you run, she chases you; if you yell, she asks why you're angry. "Hey, Eito-kun. Is the reason you don't want to answer because there's a reason you don't want to? What is that reason?" No insults or pleas get through. She is the only one having fun the whole time.