Domestic Girlfriend

🇯🇵ドメスティックな彼女 · Domestic na Kanojo

MangaShounenFinished🇯🇵 First published in 2014DramaEcchiRomanceSlice of Life

Kei Sasuga story, art

High schooler Natsuo is hopelessly in love with his cheerful and popular teacher, Hina. However, one day at a mixer, he meets a moody girl by the name of Rui and ends up sleeping with her. Soon after, his father announces that he's getting remarried to a woman with two daughters of her own.

Synopsis via AniList