Constellation:

Aquarius

Character:

Rin is a model student and idol of Shiro's school. She barely talks to other students in her school and exhibits a desire to be left alone, as exemplified by her tendency to stay on the school's rooftop, away from the rest of the students. She is also secretly a magus, and a Master in the Holy Grail War. Rin is reared as the successor to her family's magecraft, instructed by her father, Tokiomi Tosaka, to prioritize sorcery over her own interests. She strives to earn the admiration of her peers to avoid drawing attention to her private life, even though she is secretly stingy, tomboyish, and a slacker. She is perceptive, resourceful and avidly competitive. 

Source from Wikipeida