When Sun, a young casanova whose job is to break women's hearts, takes on a new assignment to break the heart of Sairung, a confident and sexy reporter for an online news outlet, things don't go as planned. In the days that follow, Sairung's personality begins to change. She becomes quiet, cold, unfriendly—and most shockingly, she doesn't even remember him, despite meeting just the day before! Curious, Sun investigates and discovers that she exhibits unusual behavior similar to someone with dissociative identity disorder—she has five distinct personalities!