Yosuga no Sora: In Solitude, Where We Are Least Alone. (Yosuga no Sora)
Kasugano Haruka and his twin sister Sora have lost both their parents in an accident, and with them all their support. They decide to move out of the city to the rural town of Okukozome, where they once spent summers with their late grandfather. At first everything seems familiar and peaceful, but then things start to change as Haruka starts to remember his youth.
[Source: Anime News Network]