In this volume, Haruhiko embarks on a class trip to Hawaii with all the regulars of the series -- Yuka, his buddies and Yukanaria. Plus an all new character: Haruhiko's former classmate Mana Kimura. Mana shares Haruhiko's love for fixing up gadgets and also has a secret crush on him What happens when Haruhiko gets involved with demons and magical weapons right in front of his friends?