Yuuichi Asaoka (浅岡 優一, Asaoka Yūichi) is Ken Kaneki's cousin.
In his youth he had short hair that appeared light colored like his mother's. He wore what appeared to be a light dress shirt and dark pants.
Not much is known about his personality, but he seems to neglect his studies and would rather spend his time playing video games. It is also evident that he was not close to his cousin as he did not complain or protest when his mother ostracized and abused Kaneki.
He appeared briefly while Kaneki thought back to his childhood. His mother and Kaneki noted that he did not do well in school and he was remembered playing video games and spending time with his immediate family.