Saitama spent most of his life as a normal guy, until one day he chose to become a hero for fun and worked extremely hard to become strong. Now too strong that he can defeat his enemies with a single punch, life again was becoming too dull. However, after meeting the cyborg, Genos (who looks up to Saitama and his immense power) and joining the Hero Association together, life begins to get more interesting.—bethanylaine789 imdb.com