Ever since Eris, a Catian alien from another planet, came to Earth and moved to Kio Kakazu's house, there has not been a dull moment. Wanting to learn more about Earth and its inhabitants, she begins investigating human pastimes by trying out different board games with Kio and other girls who have their eyes on the boy. To spice things up, the group decides to have various humiliating materials as the prizes. Even though the stakes are high, they are sure to have fun together.