Koashi Mutsumi is a girl who adores fighting games.

She is a character in Alice Gear Aegis, appearing in the work as a beginner warrior. Though a beginner as a warrior, she joined the group in the somewhat unusual form of being scouted, and she possesses high skill.

She loves fighting games passionately, and the place where she was scouted was a game center. Her personality is stoic and she is a very serious and diligent worker. Her reflexes and observational skills, honed through gaming, are particularly high, and she excels in strategic battles.

On the battlefield, she uses a sniper rifle with high annihilation power, taking advantage of her wide field of view, and fights in close combat with a hammer. Her strikes are quite heavy, giving her an advantage in boss battles, but she also has a weakness in struggling somewhat with lesser enemies.