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Mahiro Mutou
Voice actor: Aya Hirano
Height: 161 cm
Weight: 49 kg
Measurements: 85 59 88
Birthday: February 29
Blood type: 0
Age: 15
Favourite colour: earth colour
Likes: noodles, Chi-chin, Sa-chan, Tokiko-chan
Dislikes: aojiro, marathon running
Special skill: not shy at all; it takes her less than five minutes to talk to a stranger as if it was an old friend
Affiliation: Ginsei Private School, boarding student
(Source: Busou Renkin #1)
Mahiro is Kazuki's younger sister, a first year student. She is very obviously his sister, which means that she can be extremely silly. An optimistic, outgoing, happy-go-lucky girl - prone to slapstick - but also very gentle. Mahiro cares a lot for her older brother.
Similarly, Mahiro is very important to Kazuki, and it is when her life is in danger that he manages to summon his busou renkin and make himself fight. In the following time, Mahiro suspects that Kazuki is not telling her the whole truth, but she does not pressure him to tell her and still supports him morally.