Onyanko Club (Kitten Club) was a large pop idol group that contained 54 members in rotation, as well as several subgroups such as Nyangilas, Ushirogami Hikaretai, and Ushiroyubi Sasaregumi (the latter two of which provided most of the soundtrack to the popular 80s anime series High School! Kimengumi.)
The group came out of the teenager’s TV show Yuyake Nyan Nyan (Meow at Dusk), shown at 5:00 PM. The stars of the show were a group of 24 cute high school girls - the Onyanko Club. All of the girls were amateurs, chosen for being normal. They chatted about things that mattered to young girls, usually in teenage slang. When the girls had tests at school, they were absent from the show and sympathised with on screen. Replacement members were recruited after a girl graduated. The club had strict rules - no smoking and no boyfriends, and a few members were expelled or dropped out. The show would showcase their latest songs and members interviewed other idols. Potential members were auditioned on the show. Male audience members could compete for the opportunity of having their picture taken with their favourite Nyan Nayn.
Nyan nyan is a widely used term for sexual activity. Many of the songs on the show had sexual content, for example, their first single translated to Don't Make Me Take Off My Sailor Uniform.
Onyanko Club debuted in 1985 with their single Sailor Fuku wo Nugasanaide, and folded in 1987, though there were several reunion appearances, including one on an episode of Hey Hey Hey Music Champ. Several big-name idols stemmed from the group, the best known being Kudo Shizuka. In late 2002, they reunited and released the single Shoumikigen.