Yosuga no Sora - In Solitude, Where We Are Least Alone.

The protagonist, Houkou Hayao decides to take a job interview at a family resto, Berry's, in order finds out what to do when he graduates. On the same day as the interview, he bumps into a certain "ojou" who just got out from the interview room in a bad mood, and binge eats at Berry's. He later ended up hanging around with her. When he gets home, he finds out that Yuuka, his "imouto," has found out that he got a job without her permission. Later, he learns that the binge-eating girl which introduces herself as Morikubo Yuna he met is a new employee like him.

The story is set in the distant mountain village of Okukozome-chou. Kasugano Haruka and his twin sister Sora have fond childhood memories of going to the village to visit their grandfather during their summer vacations. However, after losing their parents in an accident, the two must move in to their grandfather's house. The twins get reacquainted with their old childhood friend Yorihime Nao, their new classmate Nakazato Ryouhei, the shrine maiden Amatsume Akira, and Akira’s friend Migiwa Kazuha. All seems peaceful and familiar. However, beneath the surface is a secret promise that the twins made with each other long ago, the whereabouts of an important lost item, and the real reason they chose to come back here.