Class de Ichiban Kawaii Gal wo Ezuke Shiteiru Hanashi

Historia

Sakura Kouzuki, a top-tier gyaru who's the star of the class and even works as a reader model, and Houri Kazami, who prefers talking otaku stuff with his comrades in the corner of the classroom. These two, who seem to live in completely different worlds, are actually step-siblings—and secretly live together as a couple. And none of their classmates know the truth. While Sakura sparkles at school, once she's home she relaxes completely and falls head over heels for Ori's cooking.

Sinopsis vía AniList (en inglés).