Haruno Kasumi is a fourth-grader. Her parents are zoologists who traveled to Africa to conduct their research. To see them off, Kasumi came to Kasumi Town. In the center of the town stands a huge mansion surrounded by forest. The mansion is owned by the Kasumi household, the family where Kasumi will stay and be cared for. The mansion has a mysterious atmosphere, and Kasumi finds a series of talking appliances. The Kasumi family calls these creatures "Henamon". In exchange for living with the family, Kasumi will help with household chores like cooking and washing. Surrounded by various interesting characters, Kasumi starts a new chapter in her life.