如月 ナツメ

Natsume is a young, attractive teacher at the school where the story takes place. He has great knowledge of Figurare and the Stellar Spinners, as well as the ability to use (and potentially create) magic potions. He serves as a guide and adviser to Sumomo and Masaharu while on their adventures in gathering the stardrops. 
The reason for his vast knowledge of Figurare and magic are due to his connection to his sister, Karin: Sumomo's mother. Supposedly, he too is from Figurare, but this has yet to be explicitly stated in the anime./

From url=http://en.wikipedia.org/wiki/Nanatsuiro_Drops#Secondary_characters