Domestic na Kanojo follows Natsuo, a teenager experiencing the pangs of unrequited love for his teacher, Hina.
In an attempt to move on, he attends a mixer and meets Rui, a detached girl who seeks to experience intimacy.
Their encounter leaves them both feeling unfulfilled, but their lives take a dramatic turn when Natsuo's father announces his remarriage.
Suddenly, Natsuo finds himself living under the same roof as both Hina and Rui, who are now his stepsisters, forcing him to navigate complicated feelings and the unexpected realities of love and family.