Yamakatsu was one of the classmates of Ganta that was killed during the attack on his class from the Red Man.
Yamakatsu was created by Jinsei Kataoka and Kazuma Kondou, who wrote and illustrated the manga respectively, to serve the purpose of a minor character for the series Deadman Wonderland. The series first began serialization in Kadokawa Shoten Shōnen Ace magazine in July 2007.
His anime counterpart was created by Koichiro Hatsumi who directed Deadman Wonderland. Ganta makes his first appearance in Chapter 1: 'Who Killed Cock Robin?' of the manga and Episode 1: Death Row in the anime. He is voiced by Shohei Kajikawa in the anime; for Funimation, he is voiced by Micah Solusod.