The plot revolves around Magami Eiko (A-ko), a red-haired teenage girl who just happens to be stronger and faster than anyone else alive. However, A-ko considers herself to be perfectly normal, and worries mostly about getting to school on time. Her best friend is Kotobuki Shiiko (C-ko), a bubbly, carefree, optimistic blonde. The two girls transfer to Graviton High School and catch the attention of Daitokuji Biko (B-ko), a brilliant but spoiled-rotten (and possibly psychotic) classmate with a knack for building mecha in no time flat.B-ko develops an unexpected crush on the innocent C-ko and is determined to get A-ko out of the picture at any cost. Her determination goes from being merely obsessive to homicidal when she realizes that she and A-ko were rivals back in kindergarten. B-ko creates a series of killer mecha to defeat A-ko before the morning bell rings. All of them are destroyed effortlessly by A-ko. In a final attempt at victory, B-ko makes the fight more personal by donning her infamous "Akagiyama-23" battlesuit and challenging A-ko to a duel, devastating the school and much of Graviton City in the process.Meanwhile, Earth is being threatened by a massive spaceship piloted by a race of female aliens from the Lepton Kingdom of Alpha-Cygni, who have come to Earth to retrieve their long-lost princess. Oddly enough, the princess turns out to be none other than C-ko; she is kidnapped by an alien operative known as "D" in the middle of A-ko and B-ko's fight and taken aboard the spaceship.A-ko and B-ko agree to put aside their differences long enough to rescue C-ko, and using the flight capabilities of the Akagiyama-23, they storm the ship.