Deep under the ground of the capital city of Tokyo exists a forgotten sunless world called "Tokyo Underground. From this world, two mysterious figures, Chelsea Rorec and Ruri Sarasa come escaping and find a temporary safe haven in the home of Rumina Asagi. Ruri is called the "Maiden of Life and an important personage in the underground world. Chelsea is Ruri's bodyguard and she helps her escape. Villains chasing them appear on Rumina's doorstep and the fierce fight continues. Ruri's miraculous power wakens Rumina's latent Wind Powers. Rumina resolves to protect Ruri from the evil forces using his new-found strength and sets off on his long journey.