Rando Rino, who is on her own since the death of her mother, transfers to Miyagami Gakuen, on the recommendation of her penpal, Mr. Poppit. Shortly after her arrival, Rino surprisingly becomes a member of the Gokujou Seitokai, the prestigious student council of Miyagami High. Rino learns that Jinguji Kanade founded Miyagami Gakuen as a place where students can live free from restrictions and that the Gokujou Seitokai was formed to ensure that freedom. The Gokujou Seitokai is divided into the three main divisions: Executive, Assault, and Covert plus the Vehicle Squad. Each of its members has her own special ability, such as special fighting techniques or weapons like cards and a yo-yo, or, in Rino's case, a living hand puppet called Pucchan.

Rino's life at Miyagami Gakuen is paved with hilarious events, but every now and then, there is a more serious and philosophical undertone.