Sumida and his schoolmate Keiko are 14 year old school kids living a dystopian existence where each of their parents' hopes and encourages them to die. Set in tsunami-hit areas of Japan about May 2011, which is used as a backdrop, the story follows roughly that of the manga of the same name wherein Sumida fights frequently with his father, is abandoned by his mother and tends to reject friendly advances of others. Eventually, he kills his father and then, assuming his life is ruined, attempts to improve society by killing "bad" people. Although not immediately obvious, what instead happens is that he attacks psychotic and violent characters, while he instead learns from Keiko and the Yakuza and people who befriended him that he himself has become "sick", eventually breaking free of the cycle of violence, but without a complete resolution of the issues raised during the movie before its end