Mikage has an older sister, Mitsuki, who was born 5 minutes before her. They haven't seen each other in awhile and rarely talk as their relationship is strained due to Mikage harboring a great deal of jealousy and resentment.
Mikage was hit by a car in what should have been a fatal car accident for her. Miraculously, she survived with only minor breaks and a few lasting scars. However, there is more to the story than even Mikage realizes right now.
She likely suffers from one form of a dissociative disorder but it has never been clinically diagnosed.
She is a registered nurse at a hospital built specifically for the NWO but also works part time at Yumezaki Municipal Hospital in Sumaru.
Her father, Daisuke Kohama, is a government official and because of this she has some influence to her name as well as being well taken care of. He is also a member of the NWO but it is kept secret whether or not he is a persona-user as well.