Shinji Saitou is a prankster who hates living on the island of Iejima. It's boring, there's nothing to do, and he would rather be free from his average, everyday life. After an incident results in him punching a classmate, he leaves school and receives a text saying that all his troubles will be fixed if he replies to the message, allowing him to become an "invisible man." Thinking that it can't possibly be true, he replies and perceives no changes to himself.

However, the next day, the classmate he fought has forgotten that Shinji was the culprit. It is then that a mysterious girl named Miki appears before him—who only he can see—introducing herself as an invisible woman and admits that she was responsible for the text he received. She reveals that he will fade from everyone's memories and they will be unable to see him, allowing him to live a truly free life. But when even his best friend, Kana Sodegi, begins to forget him, Shinji must find a way to fix his mistake, in order to reunite with the one he cares for most.