Shinichiro, a former detective, is currently engaged in running a nursery. He wishes to help families by offering low fees for childcare. To replenish the budget, Shinichiro opens a private detective agency at night.

Shinichiro Hanasaki is a former detective with the police department, which is currently engaged in the nursery "Smiling Garden". Wishing to help poorer families and single parents are very low fees for childcare, but this means that it is still far broke. To replenish the budget decides that during the night will have a private detective agency.