Commander, Please Do Something About That Charm! ~ The Magicless Attendant Will Not Be Seduced

https://ebookjapan.yahoo.co.jp/books/943511/
Ariane, a "magicless" person at the bottom of society, is the daughter of a viscount, but she works as a cleaner in the palace to support her younger brother. On her friend's recommendation, she takes on a new job: caretaker to the knight commander, Nightlay, who is known for overwhelming charm. The only condition for employment is "Do not fall for his charms." She starts the job for the money, but...