A magus is clever in the manner that they never reveal their true selves easily. They keep up a facade as an additional security precaution so it shouldn't come as a shock that Rin's outside personality is surprisingly deceptive. As a student, Rin is considered nothing less than an idol - admired, desired, and with her fair share of enemies. With the illusion of perfectly without any flaws due to her excellent grades and her fit physical condition, most students are afraid to approach her. Cold, but in a formal manner, Rin cares little for companionship during her time at school. She goes out of her way particularly to avoid making friends - for example, she turns down being a part of the student council despite how good such a position would look on her records. Those who gain the courage are instantaneously shot down without mercy. After all, what good is a guise if you let someone get close?

It's no good at all. In fact, it's pretty useless when you end up with a persistent servant or whenever you fall in love. In the case of Shirou Emiya, he discovers quite early on that the Rin Tohsaka he admired is nothing but a sham ('Even when I put it nicely, she's sour, cranky, unapproachable, and she's so different that I want to scream out'). She's hesitant to allow people to get close to her. Solitude has been her life as a magus for so long and permitting people to get close is a weakness. She's vulnerable (not that she would ever confess to such a thing). Her true personality is much more demonic and witchly as Shirou often thinks. Antagonizing those who get close to her, she's rather mischievous and takes delight in embarrassing others. Asserting her dominance in this manner leads back into her better-than-you attitude she has as a idol as a link to show she's not completely flawless in her guise. That is okay though, because whenever you turn the teasing back on her... well, her major character trait shines through.

This girl's distinguished personality trait can be described in a single trope. Rin is one of the notorious characters for being tsundere. As her relationship with Shirou grows, the behavioral traits of a tsundere make themselves more and more obvious. As the Second Owner to Fuyuki City, it is the charge of her family to keep watch over the area. You can assume she's rather disciplined when she puts her mind to it due not only to her proficiency with magecraft, but with her skills in Chinese martial arts. She won't hesitate to use her magic to assist her in combat, whether it's to reinforce her body to go beyond the limit or to initiate a brilliant strategy. As an Average One, she's valued by the Mage's Association and is quite the important person in the magical world, to the point where she is able to bring Shirou (a worthless magus in all actuality) with her to London. She's not a flawless magus though. Despite all of her brain power, she still has the horrible habit of making mistakes at the most crucial time.