Mana arrives at a village for a social studies field trip along with the rest of her class. When she chases her classmates around for not cleaning like they were supposed to, they inadvertently knock over an old stone monument. After that, her classmates' physical conditions collapsed and were both hospitalized. Strange things start happening around Mana as well. When Kitarō and the others investigate after sensing powerful yōkai activity, they discover Mana trapped in a mirror! Is Kagami-Jijii responsible? What was the purpose of bringing Mana into the mirror world? When Kitarō and his friends find Kagami-Jijii and question him, they get attacked with a mirror!