A normal high school boy suddenly finds a doll-like robot in his room; the robot exclaims that she is the boy's wife, then a beautiful girl emerges from its mouth.

Sanpeita is having problems with Kemeko and her pilot, Mei Mishima.

M.M. pilots the mech known as Kemeko to protect her fiancé from the efforts of the elusive Mishima Corporation who is deeply interested in a mysterious power that is hidden within his body.

Kemeko helps around the house.