You are nothing but normal high school student who love volleyball and live alone in apartment with your single mother who raised you since you born into this world. One day, your mother telling you the news about how she wanting to adopt a child from orphanage. You thought that your mother just make a joke because of how she loves to make a joke so you just let it go. But, what you don't know is that your mother not only adopts a child but children. Now, it's your job to take your new brothers during your stay in training summer camp. (Haikyuu x Kuroko no Basket)