Rin Tohsaka (遠坂 凛, Tōsaka Rin?) is one of the three main heroines of Fate/stay night who acts as the Master of Archer in the Fifth Holy Grail War. She is the current head of the Tohsaka family and the biological older sister of Sakura Matou.

Rin is a perceptive, serious, resourceful, and very competitive person. Though she is widely admired at school as a prim and proper honor student, it is a front she puts up in order to prevent others from prying into her life. In private, she is notably loud, shrewd, stingy, and bossy but usually means well for those she cares about. She is known as a model student and idol of her school. Her manner of speech is often hostile and dismissive of other people, but deep down she has a caring, big-sisterly disposition. Her tendency of making trivial mistakes at the worst possible moment is a hereditary curse. Though she really is a lot nicer than she seems, she claims to always make her decisions based on cold, rational logic in the end. In her own words, it's "not a very cute personality". In fact, her choice in personal clothes is probably an overreaction to that.[18] Despite claiming that she would do anything in order to win the Holy Grail War, no matter how underhanded, she has a deeply rooted sense of honor, seen refusing to dispose of Shirou despite numerous easy chances of doing so, simply because she owes him and deem disposing of him without clearing her debts to be cheap. In short, Rin is a tough, fiery, perceptive, judicious, mischievous, and considerably aggressive tsundere who shows both sides of the trope.