Wataru's younger brother, Isamu, once dreamed of making it big as a rugby player. But he somehow ended up living in a sharehouse with a bunch of aliens! They only want to live quietly on Earth, and in time Isamu comes to accept them. But before long, the alien housemates drawn into a conflict with an evil space crime syndicate over a shark-whale, which can raised to become a dangerous weapon! Isamu is dragged into their struggle, and it seems that the matter will be settled over... a game of rugby!?
