Mizuki is a moody person, and Kanade thinks they only act on their own principles. They tend to get frustrated and upset when ridiculed, and strongly desire to express themselves freely, without holding back or being made fun of. They have an obsession with cute things, expressing it through their hand-altered fashion.
Despite their energetic, carefree, and sometimes childish demeanor, Mizuki is often shown to be the most mature member of their circle, as Ena admits in one of her card stories.