Catia is a race of cat-like aliens who come to Earth in Cat Planet Cuties. Eris is Catian, and toward the end of the anime series, the human boy Kio becomes a catboy. In Cat Planet Cuties, Catians are shown to be sexy, alluring and kindhearted young women with cat ears and tails.
When a Catian goes through heat (similar to that of a regular cat) she becomes very emotional and sexual, and as a result must mate immediately. When Eris goes through her first heat at the customary age of sixteen, she must take medicine to calm herself down because it interferes with her job.
Because Catian males are very rare, polygamous marriages are allowed in Catian law. Catians go into periods of extreme sexual behavior or mating seasons, with their first time at age 16. Normally they have stimulus devices to satisfy their desire to procreate, though Eris wishes to have Kio as her mate.