A witch who has settled down in the Scarlet Devil Mansion. Unlike the mistress of the house, she is not weak against sunlight; however, she does not go out much. She spends her days in a library where the sunlight cannot reach. This is so that the books won't be damaged, but the unhealthy atmosphere is bad for her health.

She doesn't have a very proactive personality, but rather always walks her own path. However, she is always interested where knowledge is concerned and will proactively go and try to acquire it. She completely depends on her books, but still makes a lot of mistakes.

Although she is quite skillful, her complete lack of physical fighting ability can't be helped. She pretty much never attempts to directly punch or kick her opponent. She makes up for this with her knowledge of a great variety of powerful magic. She's more at ease using magic than trying to attack physically. Dividing the magic she uses according to the days of the week is a secret hobby of hers, but no one has realized this.

(Source: Touhou Wiki)