Gabimaru the Hollow, a former ninja assassin of Iwagakure who is known and feared as a heartless husk of a man, spends his days on death row wondering when an executioner skilled enough to so much as harm him will arrive, as he thinks nothing of seeing an end to his meaningless existence... Or so he thought. After a skilled female executioner belonging to the Yamada clan by the name of Yamada Asaemon Sagiri confronts him, she makes the young ninja open his eyes to the fact that he wants live in order to reunite with his wife and offers him a proposition. If he ever wishes to see his beloved wife again, he is, under the auspices of the shogunate, to embark on a perilous voyage to the mysterious mystic island said to house the Elixir of Life. Should he be the one among many rival death-row fiends and scoundrels to find the elixir, he will earn a full exoneration, and, more importantly, a chance at an ordinary married life with the light of his life--the woman who made the world seem not so ugly. What awaits them is a journey like no other.
While in the floodgates, Rien senses the tremors coming from the outside and is reported by Gui Fa that the Tensens have been killed, the Rite of Just Consumption has failed, and human reinforcements have arrived, who notes that a few are skilled in raids. With no other choice, Rien stages a counter attack by sending the Dōshi out for battle to buy time. Hōrai then becomes a battlefield with each side fighting against one another.