His Majesty the Demon King's Housekeeper, Volume 3 (His Majesty the Demon King's Housekeeper #9-12)

Even when she finds herself in an unknown land as the guest of a demon king, Sakura can't help herself from scrubbing the whole castle top to bottom. She's making the castle as sparkling as her smile, until a hero crashes through the window! He's here to rescue Sakura from the suddenly possessive demon king. Doesn't he realize he is tracking mud all over the floor?!