A-ko (the daughter of superheroes) is the brawn, B-ko (a mecha girl prodigy) is the brains, and C-ko (one of the most annoying crybabies in the history of anime) is, well, C-ko. They'd make a great team, but A-ko and B-ko are rivals for C-ko's friendship, and if that wasn't confusing enough, there's an army of extra-planetary forces gunning for her too. The battle begins, though not without some comedy!

In the alternate story, the Project A-ko characters all fulfill their familiar roles: A-ko provides the brute strength, B-ko assists with bizarre inventions, and C-ko is the damsel in distress. But this time, A-ko and B-ko work together from the start to rescue C-ko and avenge the destruction of their house.