Mirei is quite a hot-tempered Wild Half cat, and belongs to Miya. She really loves her master, and always tries to protect Miya the best she can. We mostly see her in her human form, going to school with Miya, posing as her 'sister'.

Sometimes she works at Luna, in both of her forms. Quite the jealous-type, she has the ability to hypnotize people, to enchant them or get them to do her bidding -- (mesmerism). This doesn't work on Taketo though, or other Wild Halves, which infuriates her, because Mirei fancies Salsa.Unrequited love, because Salsa either doesn't know or doesn't care...

In the beginning, Mirei is introduced as a sexy/evil woman who seeks to kill Taketo. This is because she has transformed into human shape and couldn't transform back to cat, and thus couldn't be with Miya anymore.

To regain her cat-traits and her predator-like thinking, she seeks for preys that will withstand her magic - Taketo was the perfect target. It was believed that her magic didn't work on Taketo because he's around Salsa so much, a fellow Wild Half.