Each of the four Sakimiya sisters are facing their own romantic challenges as they navigate relationships with women. The oldest sister, Ryou, is romantically involved with her student, Hikari. Serina, the second sister, harbors feelings for one of her colleagues at work. Yuika, the third sister, is interested in her childhood friend, Miu. Mizuki, the youngest sister, is currently dating Tachibana, a member of her basketball team.