When The Night Strike

Diether is a man of a few words. Being unreachable because of him being silent specially about his private matters is quite rude and weird for his classmate making him an outcast and the best target for bullying.

Onenight while doing his job he run into a troublesome ghost whose daughter is a little extra ordinary.
A woman name Maria who has the ability to see Lost souls or Zero and ofcourse, can see him in that form. With his mouth slightly open and a little confused he sent the old man's soul into the other world and a mission was passed down to him. A Royal Command that is unbreakable.

What will happen to him if this Royal Command is something that will turn his life up-side-down and now that a certain not-so-human came to his life and live with him?