It hands you a runaway-brother reunion setup and then refuses to do anything serious with it, and that's the whole joke. Kou walks into the slums on a rescue mission, finds Takumi running the Mikuni Detective Agency, and somehow ends up on the payroll doing odd jobs instead of dragging anybody home. The detective part is mostly a rumor. What you actually get is a few minutes at a time of grown men and one stubborn kid loafing around an office, bickering, and escalating nonsense until the credits cut them off mid-bit. No spectacle, no stakes, no case of the week that matters, just the specific comedy of a family reunion that quietly turns into a job. Twelve shorts later Kou still hasn't convinced Takumi to come back, and he's stopped bringing it up.

Kou heads into the slums in search of Takumi, his older brother who ran away from home years ago and went missing. He finds him with surprising ease, and learns that Takumi now runs the Mikuni Detective Agency and has no plans to return. Kou cannot persuade him to come back, and he does not want to go home himself, so he joins the agency and takes on errands, chores and odd jobs. Working there, the brothers cross paths with a range of interesting people. Twelve short episodes of comedy with a slice-of-life feel.