During a monster assault on the city, which occurs frequently, Silk and her two pals strive to get near to the attacking monster for a better look. Due to an unlucky choice of viewing point, UFO-man, the city's huge defender, lands on the girls, crushing them to death. Feeling sad for their deaths, UFO-man blames the monster and pledges to bring Silk and her companions back to life by giving them his strength, but the catch is that they must now also become the city's guardian.