In October 1987, during the autumn season, the Kinoshita family lives in Suganami, Tokyo. The father, a regular salaryman, earns a modest income. To cover expenses, he rents out the second floor of their apartment. One day, a determined old dog, accompanied by a younger boy-dog, knocks on their door. The elderly dog introduces himself as Norayama Kuroyoshi and his grandson as Norakuro. He wishes to open a detective agency and intends to rent the unit for their office. He will serve as president of the bureau, while Norakuro-kun will be director. He will also recruit one of the Kinoshita’s sons, Keita‑kun, as...