Mana appears in the Silent Mobius manga
series, who is the direct commander of the women of the AMP
. She leads them against the Lucifer Hawks
who are attempting to destroy the planet, with her awesome powers. Originally she is disliked because she is strict and cold towards her subordinates but she earns their respect through her dedication and loyalty to the other women.
Mana has a dark past, concerning the demon sword Medium. When Project Gaia was executed, she was possessed by it and caused chaos in the alliance of magicians who had been assembled to ensure the project's success. It is at her bequest that it is released from storage and almost creates a huge tragedy for AMP. One of her few friends is Nami Yamigumo's elder sister, Nana, which we see in Volume 4.
She uses Buddhist incantations as the source of her power. When she joins AMP (in the manga), Nami is infected with a Lucifer Hawk that tries to absorb her. Fortunately Mana's powers allow her to destroy the Lucifer Hawk and purify its evil prescence from the young miko.
The anime detracts from the manga in terms of when Mana joins the AMP. It the manga she does not join until Volume 4, in 2027. However in the anime she is already a member when Katsumi Liqueur comes to Tokyo for the first time and then joins herself.