The Black Tangerine Girl's Diary

An Yan has a younger sister staying with her, the daughter of her parents' friends. Because of work, An Yan's parents are away from home most of the year. An Yan only wants to do her best to be a good big sister, but for some reason, her relationship with her sister keeps getting worse. One day, An Yan accidentally catches sight of her sister's diary. Unable to stop herself, she opens it and sees another side of her sister. An Yan hurriedly closes the diary, hoping to forget what she just read, but when she looks up, her sister is standing in the doorway.

"You saw it."

"I... I just happened to pick up this diary."

"Since you already know, Big Sis..."