Nurugai is the last remaining member of the Sanka and a wrongly convicted death-row criminal. After the shogun called for convicted criminals to acquire the Elixir of Life from the dangerous island known as Kotaku, in exchange for a pardon for their past crimes, Nurugai accepted the invitation to be a part of the competition mission. Upon taking the mission, Yamada Asaemon Tensa was chosen as her assigned monitor.