Kuon Aiko is a 23-year-old girl who works for an undertaker. At the funeral of a boy she loved long ago, she met his brother, Kiyomi who looks down on others and the deceased man's unfriendly son, Ren.

Seeing Ren has no other relatives, Aiko confronts Kiyomi and asked him to take care of him. Surprisingly, Kiyomi blurts out an outrageous condition: "Become my servant!"