Domestic Girlfriend

Domestic Girlfriend (ドメスティックな彼女, Domestic na Kanojo) is a manga series written and illustrated by Kei Sasuga and serialized in Kodansha's Weekly Shōnen Magazine. Kodansha USA publishes the English-language translation of the manga via digital download.

Plot
Natsuo is an ordinary high school student living with his dad as his mother passed away when he was younger. Natsuo wants to be a writer trying to write in his spare time and has a secret crush on his English high school teacher, Hina but is too afraid to show his feelings. To get over his feelings and try to forget about Hina he goes out with friends and meets Rui, who is totally unsociable and unable to hold a conversation but invites him home with her! She does not want to start a relationship, nor does she care about Natsuo, she just wants to have sex because she is a virgin and doubtful she can find 'love' or a boyfriend.

Without much thought Natsuo agrees but afterwards feels guilty for losing his virginity to a girl he doesn't really particularly like. Just having sex with a girl he just met makes him feel he betrayed his crush to Hina. In a twist of fate his father announces that he is getting remarried and a love triangle full of surprises gradually unfolds as Natsuo, Rui, and Hina all end up becoming part of the same family and living under the same roof. The story point is Natsuo love-triangle style with slice of life element with humorous scenes.