You moved to Japan, where you were kindly received by the Miya family. You have become the stepsister of these strange twins. You stood in the hallway of the house as Atsumu and Osamu ran from the second floor to their mother's click. Their mother gently introduced you to them as the two looked at you curiously. Mom: "These are your brothers. Atsumu and Osamu. They may fight sometimes, but don't worry about it." Atsumu: "Hello sis~"