Id invaded denshin katsuyama
Not much is known about Katsuyama's early life, however, based on observations of his id well by Uraido, it is heavily implied that his childhood was a cruel, harrowing one, enough to mould him into a twisted, violent sadomasochist. At some point, he entered Kiki Asukai's dreams, where he met…
Katsuyama was a middle-aged muscular man with short gray hair with a combover and green eyes. He wore a black sweater with a geometric pattern on the lower torso and white marks along the collar and shoulders, and khaki trousers.
Although Katsuyama initially presents himself as an affable, formal person, this simply serves to hide his true nature: a belligerent psychopath. He was characterized by his thirst for combat, taking a disturbing amount of enjoyment in not just the act of hurting others, but in being hurt himself, which eventually led him to attack
A recreation of him appears in the “well within the well” that Narihisago finds himself in based on the past of the present world where his wife and daughter are still alive. Retaining full memories of the present, Narihisago visits Katsuyama in his home knowing he is “The Challenger” and formally challenges the latter inside his manor.
Katsuyama lets him pass admitting to his crimes but confused to the future events that Narihisago is alluding to. While inside the manor, he takes his clothes off leaving him in fighting gear as Narihisago attacks the serial killer, confronting him as the pervert who killed a 14-year-old girl. Katsuyama soon proves to be the superior fighter, knocking him down and breaking Narihisago’s left arm, while still confused at the crimes Narihisago is accusing him of and mocking his lack of skill. Narihisago however uses his gun to shoot at his thighs, to which Katsuyama wondered if they weren’t going to fight like adults. Narihisago retorts that he merely said they’d do it “Katsuyama’s way” at one vs one.
As Uraido travels from id well to id well within his own well, he eventually ends up in Katsuyama’s: a bath full of blood and teeming with sharks, with a giant fetus representing Katsuyama in the middle. Perching on his head, Uraido remarks that Katsuyama’s first memory must have been a cruel one.
Hondomachi’s first mission in an Id Well is no murder-of-the-week, but could be the key to everything. The Id Well in question is Narihisago Akihito’s, taken from still-strong cognition particles found at the sight where he emptied a clip into Katsuyama Denshin, the man who killed his daughter Muku.
