|This article is about a/an monster in the Kamen Rider Series.|
Mieko was once a normal human until she was kidnapped by Shocker. She got married with a man called Kenji in Shocker's jailhouse.
When Takeshi Hongo and Hayato Ichimonji defeated Shocker in 1973, she and her husband were free, but later Scissors Jaguar appeared and asked them to join Destron. Kenji refused and be killed by Scissors Jaguar. Meiko became mad and decided to take revenge against Destron and the Double Riders, then disappeared in the deep sea.
- Hidoragen was based on an unused Shocker monster in a 1971 card collection game.