Unokichi , the grandchild of Edo’s wealthiest merchant Mikuniya Tokuemon, becomes a constable in an unexpected turn of events. His immense wealth and detached manner amazes his colleagues. However, Unokichi does not care at all. He is hopeless with the sword, cannot run and is afraid of the dark. Although he is totally unsuitable for the job, he keeps causing misunderstandings with the people around him as he solves many cases that occur in Edo with their help.