It's about a boy who can go back in time (reset the day) but only if he drowns and he wants to be a hero
Is it this ? http://www.mangago.me/read-manga/boku_dake_ga_inai_machi/
Saike mata shitemo
Yes is that one! Thanks
It's about a boy who can go back in time (reset the day) but only if he drowns and he wants to be a hero