Yosuga no Sora

Kasugano Haruka and his twin sister Sora spent summers in the remote mountain village of Okukozome-chou visiting their grandfather. After their parents die in an accident, the siblings are forced to relocate there permanently. They reconnect with Yorihime Nao, a childhood friend, as well as Nakazato Ryouhei, a new classmate, and Amatsume Akira, a shrine maiden, along with Akira's companion Migiwa Kazuha. At first, the village feels comforting and familiar. Yet, hidden beneath this normalcy are a secret promise the twins once made, the location of a significant lost object, and the true reason for their return to the village.