The story takes place in Ueno Park. In this seemingly ordinary park, there is actually a small justice team "COLORS", and the members of the team are all cute and lively elementary school girls. In order to protect the peace of Ueno and drive away the bad guys who are trying to plot, the three girls work hard every day. Yui (voiced by Takada Yuki) is the leader of COLORS, and has an aura that unites people. Although she is a very timid crybaby on weekdays, once she is angered, she will show a very scary side. Xiao Xing (voiced by Takano Marika) runs a fruit and vegetable store at home. She is the type who acts one step ahead of her mind, which often makes her laugh. Qinye (voiced by Hioka Natsumi) is a homegirl who is addicted to games.