Yukari Yakumo is youkai sage of Gensokyo who is able to manipulate all boundaries. She is one of the responsibles for creating the boundaries of Gensokyo while also maintaining the society of Gensokyo. She is the master of Ran Yakumo, of whom is the master of Chen. Yukari is a very "youkai-like" youkai, in that she desires mostly to just eat good and sleep well, to which she often hibernates during winter time. However, she controls things behind the scenes, keeping balance in Gensokyo. 