소개：취미로 영웅을 시작한 사이타마가 3년간의 특훈을 통해 무적의 힘을 손에 넣어 모든 적을 일격·원펀치로 이기는 영웅이 되고, 어쩌다 제자가 된 제노스와 함께 히어로 협회에서 정식 영웅 활동을 시작하게 된다. 괴인 발생률이 높아져 가는 중 대 예언가 지바바와가 남긴 지구가 위험하다는 예언에 대책을 마련하려는 히어로협회, 그리고 그곳에 영웅들을 뒤쫓는 가로우가 나타난다.
소개：In the world of fandom, nothing is too much. Being a fanatic of something makes our lives exciting, meaningful, and fulfilling. This fanatic romance comedy will show you what it takes to be a fanatic fan, and what it means to be a “Deokhoo”, fangirl. Sung Deok Mi is one such person who takes her professional life serious, and someone who takes her private life of being a fanatic fan even more. Ryan Gold, who is a man drenched with success, enters Deok Mi’s life at the Chaeum Art Gallery as the new director and slowly starts to fall for her charms. After slowly getting to know each other, Ryan learns Deok Mi is a serious fan of Cha Shi An, an idol singer, of whom she secretly runs a fan page of. And through her craze, he starts to take interest in being a fan himself and gradually delves into the life of being a fanatic fan. Watch as these two characters take the meaning of being a fan to a new level as they fall in love.