My Condolences, but Starting Today You're My Wife

Overview

"Well then, how much will you pay to have me?" - Office worker Sumika has lived in perpetual mourning since losing Haruki, her first love who once lifted her out of the grief of losing her only family. A friend from work drags her out to a party, and there she meets Mr. Katsuragi, the vice president of the company hosting the party. It ought to be their first time meeting... and yet, he gives off the impression of already knowing Sumika very well. On top of that, just when Sumika is at her wits' end trying to think of a way to save the family that took her in, Mr. Katsuragi offers to buy her hand in marriage...? (Source: MangaPlaza)

Source: AniList