御薙 鈴莉

She is a teacher in the magical section. 

She is the biological mother of Yuuma Kohinata. She was forced to entrust her son, Yuuma, to her close friend, Otoha, because of many tragic things that had happened. She erased Yuuma's memory of her before going separate ways. She revealed the whole story to Haruhi and Anri of what had happened in the past./

Taken from url=http://en.wikipedia.org/wiki/Happiness!#Characters