Genius inventor Null tragically loses her older sister Peta in an accident. To get over the grief, Null develops "Peta Robo," a robot with the same characteristics as her late sister. However, the robot is a little different as to what Null expected. (Source: MAL News)

The anime centers on four girls at the full bloom of their youth, working hard to achieve their dreams as they struggle valiantly. In Japanese entertainment, Maesetsu! refers to an introductory talk or explanation addressed to the audience before the broadcast of television programs, usually performed by assistant directors and particularly comedians in variety or comedy shows.

Jouji Gouda is a new transfer student at Hakuryo High. He fell in love at first sight and boldly proposed to Akane Suzumiya, representative of his class, on his first day at the new school. Although Akane finds him very annoying, hot-blooded and simple-minded Jouji never gives up and would do anything to express his love towards Akane.

The ancient kingdom of Parros has been invaded by the armies of Mongaul, and its king and queen have been slain. But the "twin pearls of Parros," the princess Rinda and the prince Remus, escape using a strange device hidden in the palace. Lost in Roodwood, they are rescued from Mongaul soldiers by a strange leopard-headed man, who has no memories except for the words "Aurra" and "Guin," which he believes to be his name.