Ruuan Keikounitten

Freed by Tasuke from a wand artifact, the kokutentou found in the same area as the shitenrin and sent to Tasuke by his father. Ruuan's role as opposed to Shaorin's is not to protect Tasuke but instead to make him happy which she does by giving inanimate objects life to do her bidding. In the manga she gets herself a job as Tasuke's homeroom teacher. Ruuan and Shao are sworn rivals and conflict often occurs as their roles of keeping Tasuke "safe" or "happy" aren't always equivalent

(Source: Wikipedia)