Ruka is described to be a cheerful, determined, and passionate girl. She is a straightforward person who is honest with her feelings. On the flip side, her traits often convey her as being pushy and possessive. This personality of hers developed after learning of her condition and being alienated from her peers. Because of this, she became very fixated on the idea that getting a boyfriend would help her in having a faster heartbeat.

Ruka's brash persona often leads to conflicts with Kazuya and,