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

Tragically orphaned by a car accident, the Kasugano twins travel to their grandparents' countryside residence in Okukozome via railcar, hoping to reconstruct the shards of a shattered life. These two lonely souls, physically alike yet spiritually divergent, are unaware of the challenges these conflicting expectations will unveil in the coming days. Uncertain of the future, Haruka Kasugano clings to memories, hoping to find the strength he needs to protect his ailing sister. As the tale develops, it tells four stories, each with one girl: Kazuha Migiwa, rich but kind; Akira Amatsume, polite but sad; Nao Yorihime, depressed but hopeful; Sora Kasugano, petite but fierce.