Season 1

Baian and Hikojiro are hired to take on a revenge killing for a dying noblewoman, who wishes them to assassinate the psychotic low-rank samurai who cruelly murdered her daughter-in-law.

Baian and Hikojiro make their preparations to take down a very dangerous target, whilst an old acquaintance returns to Edo for a showdown.

A young maid witnesses Baian carrying out an assassination. Although the code demands that he eliminates any witness, Baian refuses to do so. Hikojiro, however, is not so sanguine about Baian's decision and decides to take action himself.

Baian's samurai friend Juugoro Kosugi accepts a contract to kill a woman but finds himself unwilling to do it. Baian agrees to take on the job, if Kosugi will kill a certain ronin in exchange. Then they discover the contracts are related.