His Majesty the Demon King's Housekeeper Series by Saiko Wadori, Mika Kajiyama

For Takatsuki Sakura, a trip to the library turns into a fantastical journey. She has been swept away to a grandiose castle ruled by a gorgeous demon king. Magic and wonder covers every room. Taking it in, Sakura can hardly breathe... because of all the dust and dirt. A curse has prevented this kingdom from cleaning. Only Sakura and her housekeeping knowhow can scrub away this dark magic grime!

Sakura is putting her neat freak habits to good use! She's wiped away the grease and grime with baking soda. Now her new citrus cleaner is cutting through alkaline build up left by the witches curse. All demons bow to the skills of housekeeper saint Sakura! But her clean streak might have caught more attention than she originally thought...