Umareru Kachi no Nakatta Jibun ga Anna no Tame ni Dekiru Ikutsuka no Koto

生まれる価値のなかった自分がアンナのためにできるいくつかのこと

A 32-year-old aspiring mangaka, Kazuya Mukai, falls off the rooftop of his old elementary school during a drunken stupor. When he wakes up, he finds himself 20 years in the past, and even his body has regressed to that of a sixth grader. Now that Kazuya has a chance redo his life that had been full of disgrace and humiliation, he hopes to win the heart of a little girl and his first crush, Anna. However, his feelings only lead a whole new tragedy. It's a puppy love that transcends the bounds of time, only to be defiled. (Source: Amazon)