A bunch of aliens seeking to take over the Earth invade Tokyo one day. Momoko, who desires to be an idol, becomes embroiled in the subsequent brawl in an unexpected way. The extraterrestrial empire's leader, Warudemon, employs a variety of strategies to hunt down Momoko and the people around her. Momoko resolves to take a stance against the violence. Wonder Momo was first launched as an arcade game in 1987. A side-scrolling beat 'em up game with a morphing, hoop-wielding heroine that is rather simple (by today's standards).