Kenichi Watanabe, a high school student nuts about his MBX50. He and his friends set up a bike club called Culture, and this story chronicles their adventures on the journey towards adult life.

Geist (the main character) is MD-02, a Most Dangerous Soldier, genetically engineered to function as a killing machine, but every one of the MDS units went homicidally insane. As a result Geist was placed in suspended animation in a stasis pod orbiting the planet Jerra until it crashed several years later, awakening him and bringing him into another war on the planet.