Brothers Ryuichi and Kotaro lost their parents in a plane crash. The one who adopted them was the chairman of Morinomiya Academy, who also lost his son and daughter-in-law in the accident. But the condition is that Ryuichi must take care of the children in the nursery set up in the academy! The nursery set up in the academy for the mother's teacher. In order to make up for the shortage of staff in the "childcare department", Ryuichi became the number one member...! ?