Gaki ni Modotte Yarinaoshi!!! - Season 1

Boku has never had any luck with women in his life and looks back on many painful memories of being bullied by the unfathomable opposite sex. He only remembers one girl in a positive light, whom he actually liked – Kasumi, his sister’s friend from the neighbourhood, who often came to visit during his childhood. But even Kasumi is now married, and everyone but him has found happiness in recent years. However, his wish to go back and do everything differently is unexpectedly fulfilled: he suddenly travels back in time and is, once again, the boy he was back then. Now, he can show the girls, who have always treated him with contempt, what he is really made of. With the experience of an adult and unbridled sexual energy, he makes up for the things that have been denied him so far!