I Can't Refuse S manga volume 5 features story and art by Ai Hibiki.

Miku's dreams of becoming a well-paid mistress are finally materializing! Her education under the hands of Hakuouin's sadistic butler has concluded and Miku's debut as an official mistress is upon her. With one last lecture, her stern butler teacher Kamishiro vanishes from her life. Despite her graduation, Miku can't help but continue to crave the steady hands and steely words of her teacher… What kind of mistress craves the butler?!