Overview
Yuugi-neesan (勇儀姐さん) is a nickname of Yuugi Hoshiguma, a character in Touhou Project. This is not one of her titles. She is kind-hearted and strong, a good woman with an older sisterly spirit.
She is called Yuugi-neesan (nee meaning sister) to express admiration of her.
For more details refer to the article Yuugi Hoshiguma.