Voir Yosuga no Sora: In Solitude, Where We Are Least Alone, Season 1 - Episode 1

After the sudden death of their parents, Haruka and his twin sister Sora move to their grandparents' house in a small village they often visited as children. There, Haruka encounters several of the residents, some of whom are old friends, but Sora stays at home, becoming more and more distant, refusing to go to school, even as Haruka starts attending classes.