One day, Nube meets a little girl in town. She is a Zashiki Warashi, a spirit that brings good fortune to people. The Zashiki Warashi becomes attached to Nube and follows him to school. From that day on, unexpected good fortune begins to befall his classmates one after another. However, as he sees how the students in his class gradually forget about hard work and start relying on good fortune, Nube finds it difficult to say goodbye to the Zashiki Warashi, but...