im getting confused on who is who ngl

Mizuki is the main character. He was working as a host and got fired.
Mr. kujo (black hair) is is the one that runs the host club and he rehired Mizuki to seduce men.
The man Mizuki is trying to seduce is the one that he went to the motel with and couldn't go further with him.

The one he is seducing is named Masumi Saeki. On the cover of the book its Mr.Kujo, Mizuki and Masumi from left to right.

thank you!