The story chronicles upon the past of Gai Kurenai and Jugglus Juggler, the original series' main protagonist and antagonist, who were once heroes fighting on the side of light, facing Dr. Psychi and his army of Bezelbs.
Shinichiro Hanasaki, a former detective with the police department, is currently engaged in running a nursery called “Smiling Garden.” He wishes to help poorer families and single parents by offering very low fees for childcare, but this leaves the nursery struggling financially. To replenish the budget, Shinichiro decides to open a private detective agency at night.