Eroi Kareshi ga Watashi wo Madowasu

Sakaino Hitomi is an honest lady from a well-to-do family. She is envied by everyone for being engaged with Akashi Keigo, a man with a good appearance, high income, high education, and kindness. Hitomi is about to get married but suddenly becomes attracted to a man, Manabu, who she met at a construction site.
(Source: DramaWiki)