The Happiness House, a colossal tree with little buildings and houses both inside and on it, is the new home of Michi and her family. While checking out her new bedroom, Michi discovers an unusual nut-shaped item. Soon enough, a peculiar being named Nanami-chan emerges from the object, and the two quickly form a close bond. With each passing day, they learn new things and encounter more quirky individuals residing on the Happiness House.