Marika Katou, a third year student at Hakuho Girls' Academy, is a legitimate space pirate with a Letter of Marque. Between her studies, leading her school's space yacht club, working part time at Cafe Lamp, and being the captain of the space pirate ship Bentenmaru, Marika's days are very busy. One day, Marika gets a job to rob a high-class passenger ship, and she discovers that on the passenger list is Kanata Mugen, a boy who owns a "galaxy pass". Thus, an adventure featuring a hyperspace race between pirates and one young boy begins.
Zorori, Ishishi, and Noshishi, while out searching for treasure, come upon a town with a widespread illness. In order to make the secret medicine for it, they must set out on an adventure.
The mysterious island of Houraijima has reappeared after 50 years, and with its reappearance has brought the attack of four gods, the Shitoushin, who have their eyes set on the powers that protect and sustain the island. Now it's up to Inuyasha and his friends, along with Sesshoumaru, to find a way to defeat the powerful Shitoushin.
