Takahashi Asanosuke is the son and heir of the headman of a town. His father arbitrates civil cases which the town’s magistrate cannot try. Asanosuke and Yagi Seijuro, the resourceful son of the neighbouring town’s headman, are skilled because they apprenticed as constables. Soma Kichigoro is their close childhood friend. Asaknosuke had been a serious and outstanding youth until the age of 16. However, he became a carefree pleasure seeker at somepoint. Though usually completely unreliable, he actually possesses exceptional deductive skills. The trivial matters of Edo’s people would be brought to him each time. However, he would skillfully solve even the most chaotic and disentangled matters with unexpected methods.