Sometime in the distant future, mankind is forced to live in domed cities while the rest of the world is left to recover from years of environmental hardships. In the Siberian Dome-polis, professional gamer Gainer Sanga and mercenary Gain Bijou commandeer an Overman and lead a mass exodus out of the city.

After the death of Saizou, Kabamaru's horribly strict grandfather and Iga ninja teacher (sensei), an old lady, Ran Ookubo, claims that she received a letter from him asking her to take care of his grandson. So Kabamaru runs off with Lady Ookubo to the big city Tokyo to gorge on yakisoba, ramen, chow mein, and attend a regular school—which turns out to have weird quirks of its own. (Source: ANN)

The story of Sanzo and his three companions in their quest to the west, to stop the resurrection of Gyuumao. On the way they are fighting youkai, getting into trouble and helping the townspeople.

The gang is traveling along when they find a girl in need. Of course, they all can't resist going after her. This girl isn't all that she seems... her motive or her "humanity".... and soon the whole gang has Sanzo's past on their hands and one certain young boy who can keep a grudge for decades...