|Killed by||Unnamed undertaker|
|Branch of Sin||Unknown|
|Manga debut||Chapter 12|
|Anime debut||Episode 8|
At some point in the past, Kosugi was imprisoned in Deadman Wonderland. Later, he joins a resistance faction within the prison known as Scar Chain.
Kosugi's hair was gray on the top, black at the sides and combed backward. He wore a bartender uniform, a white shirt and a black waistcoat that had a pocket on its left side where a pen was held. He also had a black, thin band around both his arms (only his left arm in the anime), as well as a death row collar around his neck.
In the anime, his right arm was a prosthetic, which can be freely removed. Underneath it was a hidden knife.
Kosugi, like most members of Scar Chain, was a kind individual. He was willing to sacrifice his life for Scar Chain's cause.
Scar Chain Arc
Kosugi first appears at the Scar Chain meeting, introducing himself to Ganta Igarashi. When Shiro asks for a snack, Kosugi, being a bartender, professionally makes her a milkshake (ice cream in the anime). After seeing how innocent she seemed, he asks her why she is in Deadman Wonderland, in which she responds that Deadman Wonderland has always been her home.
He was present during Nagi Kengamine and Karako Koshio's presentation about the planned breakout. When the prison break began, Kosugi joined the first Scar Chain group in an attempt to escape to the elevator. After coming off the elevator, he and the others were interrupted by the Undertakers as they started to attack them.
As Kosugi fends off the Undertakers, he pulls Ganta aside, telling him he must get the data chip to the surface at any cost. As he hands over the data chip, an Undertaker ambushes them from above. Kosugi takes a sharp metal bar (a hidden knife from his prosthetic arm in the anime) in an attempt to protect Ganta, which ends with him and the Undertaker taking each other out simultaneously. Kosugi, desperately, utters to Ganta that the data chip is their only hope and dies shortly afterward.
Hidden knife: In the anime, his right arm is a metal prosthetic, under which he hides a small knife.
In the manga, he uses a sharp metal bar in order to defend Ganta from the Undertaker, simultaneously taking each other out.
Branch of Sin: Kosugi was a Deadman and as such, had the ability to freely control his blood outside of his body. His personalized Branch of Sin was never shown.
|G Ward||Kiyomasa Senji · Minatsuki Takami · Chaplin Sukegawa · Idaki Hitara · Itadaki "Masu" Kazuya · Mitsuzaki Yosuga · Toto Sakigami · Albatross · King Fisher|
|Scar Chain||Ganta Igarashi · Nagi Kengamine · Karako Koshio · Bundō Rokuro · Endō · Ohara · Kosugi · Kōmoto · Miya/Harumi · Wakabayashi · Yamazaki · Akiyama · Ueshima · Miyako · Kazu · Fujiyoshi/Matayoshi · Unnamed Deadman 1 · Unnamed Deadman 2 · Unnamed Deadman 3|
|Other||Shiro · Wretched Egg · Red Man · Chan and En · Hagire Rinichirō · Keigo Ugachi|