"Your too bright turn in down!" Park Min young is the younger sister of Park Chanyeol, the happy virus of EXO. Park Min young is the same way, cheerful and happy. The siblings are very close but the only problem is Min young lives in America not Korea. But what happens when Min young and her best friend, Kim Luna, go to Korea to live there for the rest of their high school life. Also what happens when they meet Seventeen and BTS. And even worse when someone from one of the groups falls in love with her. Will she remain a happy virus? Or will she crumble? You know what they say sometimes the happiest of people can crumble the easiest.