There's only 2 days left of summer vacation. Naoki's father and Kotoko's father go to Kyushu for a reunion party. Naoki's mother has to urgently return to her hometown to see her sick mother and takes Naoki's little brother Yuki with her. Naoki and Kotoko have to spend 2 days alone together?! Despite all this, Kotoko is panicking about her summer homework. She sneaks into Naoki's room to copy his notebook... "Are you here to attack me secretly"...?