Masaharu Tsuwabuki is a normal student, though not very social. One day he meets a new student named Sumomo Akihime, and another girl named Yaeno Nadeshiko, Sumomo's close friend. That same afternoon, he suddenly bumps into Arthur, a servant of Nona Yuki from Figurare who at the time was disguised with a mask. The collision causes Arthur to drop a bag full of magical potions; amid gathering up the scattered cans, one of them is accidentally switched with Masaharu's soda can. Upon drinking it, he transforms into a stuffed animal lamb at night. He must collect seven stardrops, in order to return to normal.
There are two primary worlds within the story of Nanatsuiro Drops: the human world called Retroscena, and a magical world called Figurare from which the Stellar Spinners originate. There are currently two schools that teach magic within Figurare: Pramu Cloris and Saint Asparas. According to Natsume, each year the two schools pick their top Stellar Spinners (the one from Pramu Cloris is called Prima Pramu, and from Saint Asparas is called Prima Asparas) to send to the human world to capture seven stardrops in a goodwill competition to improve relations.
