週刊ヤングサンデー
is a "seinen" manga series written and illustrated by Hideo Yamamoto. The series revolves around Ichi, a psychologically troubled killing machine, and his confrontation with the yakuza of Kabukichō, Shinjuku. The manga was serialized in the Shogakukan magazine "Weekly Young Sunday" from 1998 to 2001 and has been collected into ten "tankōbon" volumes in Japan.