Doinaka Shusshin no Imo Reijou, Nazeka Koushaku ni Dekiai Sareru

Overview

Even with those eyes, you can't understand love! Vivi, a young lady from the countryside who came to the royal capital to work in order to maintain the reputation of her baron family, is a seamstress who prioritizes functionality. Alex, the leader of the Holy Knights, happens to meet Vivi and falls in love at first sight! His doting heart never stops, and they end up living together!? There seems to be a deeper reason behind his actions, but to Vivi, who has no experience with love, it's all incomprehensible... The devoted love of the handsome, scheming duke is too much for a young lady like her. (Source: Kadokawa, translated)

Source: AniList