Madoka Orimura, generally known by her alias M, is one of the primary antagonists of the light novel and anime series Infinite Stratos. She is a member of Phantom Task, the younger sister of Chifuyu Orimura and the twin sister of Ichika Orimura.
M was the one who raised the plan in Phantom Task to steal Byakushiki during IS Academy's anniversary. She was also responsible for a device called the 'Remover', that almost caused Ichika to lose his IS when he was fighting Autumn during the IS Academy school anniversary.
After invading and terrorizing the USA base to steal The Steal Gospel, she is intercepted and defeated by Natasha. After finally her revealing true name for intention to kill Ichika, she attempts to murder him, but Laura deviated the attack.
Her personality is almost the exact opposite of Ichika's. She is cold-blooded, quiet, and prideful, always looking down on almost everybody but doesn't say it out loud. So far in the Light Novel series, she only has one goal and that is to kill Chifuyu Orimura, and on occasions she plans to also kill Ichika Orimura.
In battle, Madoka is very cool-headed and sadistic, as she would both mock and at times toy with her opponents. She complains about how weak the guards are compared to her in the first episode of the second season. She also doesn't seem to care who she hurts when it comes to getting what she wants. Likewise, she finds it more bothering to not kill someone in her way than it is to just kill them. But when ordered to or when she can't afford to, she'll simply try to deal with them as fast as she could.