Tohma asks Rui to return to the Marikiri household—as an official, certified butler! Rui, overjoyed, sets her sights on passing the harsh certification exam… and, of course, she must continue to hide the fact that she's a woman or risk being disqualified outright! Hatarai-sempai's guidance and instruction is crucial to passing, but as the intimacy between them grows, so do Rui's feelings! Between Tohma, Haruki, and Hatarai, how can she choose?!