Saikyou Kawaii Mibou Reijou Kojima-san: Watashi wa Maid ja Arimasen

Dimitri, a boy who was being attacked by a beast in the forest, meets Kojima-san, a 17-year-old widowed maid (self-proclaimed housekeeper)!! Kojima-san is said to be treated poorly by her fiancé and mother-in-law as a housekeeper—not a maid—for a certain reason. Dimitri, who has been injured, is nursed by Kojima-san, and as they spend time together, he learns about her outrageous strength and the cuteness she shows from time to time, even though she looks mature...? Expressionless but the strongest and cutest Kojima-san meets a boy, and they take a new step forward together…

(Source: Flex Comix, translated)