Marina, a high school girl living with her brother, continued to live together after her brother got married and brought in his wife Akari. One day, she was told by Akari that her brother was cheating despite being newlywed, making things awkward. However, Marina was also cheated on by her boyfriend. As they comforted each other, the two grew closer. Akari had been bisexual all along but had suppressed it due to marriage.
