夏休みも残りわずか2日となったある日。琴子の父と直樹の父は、同窓会に参加するために九州へと旅立った。そこに電話が掛かってきて、直樹の母も実家の母の急病のため、直樹の弟･裕樹を連れて出掛けるという。2日間、直樹とふたりっきりで過ごさなければならない!? 慌てる琴子だったが、夏休みの宿題でそれどころじゃない! 直樹のノートを写そうと部屋に忍び込んだが、｢夜這いしに来たんだろ｣と迫られて......!? Only two more days of summer break left. Kotoko's father and Naoki's mother departed to Kyushu to participate a class reunion. There's a phone call where Kotoko learns that Naoki's mother has to take care of their grandmother who had suddenly fallen ill, and she takes Naoki's little brother Yuuki with her. Kotoko now has to spend two days alone with Naoki!? Kotoko panics, but she had no time to as she still has to finish her summer break homework! She tries to sneak into Naoki's room to copy his notes, but is caught by him while being accused to be "trying to get under the covers with him at night"...!?