Recently, my sister is unusual.

Mitsuki Kanzaki is a high school freshman struggling to adjust to her new family situation after her parents remarry. Her stepfather and stepbrother, Yuuya, have just moved in, but Mitsuki's past experiences with abusive father figures have left her wary. After a car accident lands her in the hospital, Mitsuki becomes possessed by the ghost of Hiyori Kotobuki, a girl who died in her teens and is stuck because of her unrequited love for Yuuya. Hiyori's presence in Mitsuki's body creates a complicated situation, forcing Mitsuki to confront her feelings about her family and herself.