Yui has lived without her mother since childhood, raised with the support of her father. As she faces upcoming exams, her father is suddenly required to go on a year-long overseas business trip. During his absence, Yui is placed in the care of her father's close friend. The friend's household includes his son, and so Yui begins her new life under one roof with them. However, one day, she is falsely accused of something she didn't do, triggering a series of strange events. The story unfolds with themes of her bond with her father and the inner conflicts she faces in this unfamiliar environment.