18+ Konya, Kimi wa Boku no Mono ni Naru

Haruko works as a housekeeper at Cunningham Hotel Tokyo. One day, the CEO, Izumi, makes a marriage proposal to her. He says that he's fallen for the two sides of her: Haruko the hotel housekeeper with exceptional skill, and Haruko in her private time, who stays in the hotel under a pseudonym.

(Source: Printemps Shuppan, translated)