High school student Ahn Hyoin gets along with her friends at school. She knows how to read the room and sometimes makes her friends laugh. Thanks to this, she gets along with everyone. However, one day, seemingly without reason, Hyoin starts to be strangely bullied. Is it because she got a smartphone late? She finds out about the existence of a group chatroom that does not include her. "I... What... Did I do something wrong?" (Source: Naver, translated)