Mighty Cat Masked Nyander (ニャニがニャンだー ニャンダーかめん, Nyani ga nyandā Nyandā Kamen) is a Japanese children's anime series produced by Sunrise, loosely based on children's book of the same name by the author Takashi Yanase. It aired on both Nagoya Broadcasting Network and TV Asahi from February 6, 2000 to September 30, 2001, with a total of 83 episodes.
In an anthropomorphic town of cats called Cat Town, Nyango is a young elementary student who is also the town's secret superhero called Masked Nyander. Always responding at a cry for help. Nyango transforms to help the people of Cat Town making him beloved by the townsfolk, while also gaining many rivals.