Mikage taught the younger Nanase on the values of being an exorcist and one's existence in this world.
However his sealing method was harmful to his body for his true form was actually that of river jade. His master saw his jade stone when he was searching for a suitable stones for sealing spirits by the river.
When Mikage grew weaker and his bad side started to manifest, he searched for Reiko, asking her to seal him so that he won't turn into evil spirit. However his request was rejected by Reiko, instead they had a battle where Reiko got his name into the Book of Friends. Mikage was considerably weaken from the battle.
Mikage then asked the young Nanase to seal him with using the last jade piece of himself. When the young Nanase refused, Mikage reassured her that she is a strong exorcist, for she knew the joy and pain of being an exorcist.
Many years later, Natsume returned Mikage's name and he returned to his original form as a jade stone.
- Main article: Nanase
- Main article: Kotengu
- Main article: Reiko Natsume