It's summer break, and they all go to the mountains to camp. Hikari and Akari learn about nature and are happy; Ioneous and Jennifer get drunk, and are also happy. The group decides to play a game in the dark where they're basically supposed to split up into pairs and stake a flag on a rock. Hikari and Takeru wind up together and the rest of the group has fun spying on them, until Ioneous in monster-form starts running around in a drunken fit, making them think they're being attacked.
待ちに待った夏休み、山へキャンプに出かけたタケルたち一行。初めてのキャンプで、川遊びや魚釣りなどを楽しむヒカリやアカリ。その夜、夏休みの定番「肝試し」をすることにした一同。タケルとペアになりうれしいヒカリと、二人きりで何を話していいか分からずあせるタケル。暗闇の中、二人の距離が急接近して…。
