Shy misfit Sio Ogura, who prefers talking about tanks instead of girl gossip stuff, has as her only friend the popular, kindhearted Asao. Sio has had reoccurring dreams of ancient battle scenes, but her life abruptly changes when a school trip is interrupted by an attack by Evolutionary Invaders, hideous alien creatures bent on conquering the planet. While attempting to rescue Asao, Sio discovers that she's an E-Gene Holder, a historical figure's reincarnation who can summon special weaponry. Her weaponry is of the legendary warrior Oda Nobunaga.
