Chinami Noki

Chinami is the vice president of the student council in the anime; thus, she is technically lower in rank than Yuriko, but she behaves as if it were the other way around, giving Yuriko orders and formulating plans on her own. However, in the manga, she is secretary of the student council. Chinami is presumably half-alien, as she has cat ears identical to Yuriko's (but Chinami's ears do not appear nearly as often as Yuriko's do). At first, she's secretly jealous of Yuriko's carefree personality and always being in the spotlight, but after being voted Queen of the Beach, she realizes that she prefers being a supporting character than a main one. After being branded and imprisoned as traitors with Yuriko, she rebels against the alien's forces. Three years later, she's seen to be working with Yuriko at their co-owned hot springs. Unlike Yuriko, she still keeps her cat ears hidden.

(Source: Wikipedia)