Domestic Girlfriend

Few things in a person's teenage years can pain them more than heartaches brought on by unrequited love. This is the situation for Natsuo Fujii, who has found himself mesmerized by Hina, a teacher at his school who is constantly happy. Natsuo is defeated by this unattainable goal, so he plays along with his buddies and goes to a mixer. There he meets Rui, a girl who shares his lack of excitement. Rui invites Natsuo to have sex with her at her home after they become friends over their shared shyness in the hopes that the encounter will stop her friends from treating her like a child. Natsuo reluctantly nods in agreement while still thinking about his hopeless feelings for Hina. The two decide to split ways as strangers because they were both equally unsatisfied by their "first times." Natsuo's father, however, shocks him by announcing that he is getting remarried and that his new wife, Tsukiko Tachibana, is coming over right away to meet Natsuo before he even gets a chance to process this experience. As if that weren't shocking enough, Hina and Rui Tachibana, the woman he is in love with and the girl he had his first night with, are her daughters and as a result, Natsuo's new sisters. As Natsuo's eyes are now opened to a darker aspect of love, he must now come to grips with his affections for his step-siblings.