Kon'yaku Haki Sareta noni Moto Kon'yakusha no Kekkonshiki ni Shoutai Saremashita. Kotowarenai node Ani no Yuujin ni Doukou Shite Moraimasu.

When low-ranking noble Lucia’s fiancé suddenly ends their engagement to marry her cousin, she’s left with quite the dilemma—being invited that very wedding! Unable to refuse, and with her brother too busy to attend and offer support, he asks his friend Phill, a soldier currently on leave, to accompany her instead. But as the days unfold, she sees there’s more to Phill than meets the eye! A broken engagement is only the beginning to this sugary-sweet Cinderella love story!

(Source: Manga UP! Global)