Ane Ane ~Yurushite! Oneechan-tachi, Boku no Ochi*chi* Dame ni Nacchau!~

Shun starts living at his cousins', Madoka and Hikari, apartment since his parents have gone abroad for business. Madoka is a university student and Hikari is a high school student same as Shun. They take good care of him, and it gradually becomes bolder and bolder. Finally, they decide to have a battle who will take Shun...