A long time ago, the woman who mowed with a strange beast, gave birth to saishes, half a human being half a beast, whose body was filled with poison. These brutal creatures were used in the battle during the riots, but in peacetime they were rejected and hated. In fact, they were damned. Samurai Ronin named Gene Tsukinosuk - one of the few survivors and the owner of the magnificent sword of the "Fang of God". He travels in search of his alienated sister and sleeps with women who crave death, killing them with their deadly poison. The story takes place in the destroyed war at the end of the Edo period. With fate to be Kaishi, Tsukinosuke is also absorbed by the harsh stream of history.