Yosuga no Sora

Yosuga no Sora (ヨスガノソラ, lit. "Sky of Connection") is a Japanese romance/drama adult visual novel developed by CUFFS ("Sphere"). The game was originally released for Windows PC on December 5, 2008. It was adapted into a serialized manga and an anime TV series. A sequel/fan disk titled Haruka na Sora was released later on October 24, 2009 which contains new and expanded scenarios for several characters from the original game.

Plot
Tragically orphaned by an automobile accident, the Kasugano twins travel to their grandparents' countryside residence via railcar, hoping to reconstruct the shards of a shattered life. With an uncertain future, Haruka Kasugano clings to memories of the past, hoping to find the strength he needs to protect his ailing sister. With a destiny irrevocably tied to that of another, Sora Kasugano clings to moments of the present, drawing comfort and security from the company of her brother. Two lonely souls so physically alike, yet spiritually divergent, unaware of the challenges these conflicting expectations will unveil in the days to come.