Gaki ni Modotte Yarinaoshi!!!

Ever since he was a kid, women have bullied Boku, which marks him so that he stays stuck in the past and becomes unable to move on with his life. One day, his childhood crush, Kasumi, invites him to her wedding. As he watches everyone around him lead a happy adult life, Boku realizes he has been left behind, causing him to wish he could start his life all over again.