Class no Daikirai na Joshi to Kekkon suru Koto ni Natta.

High school student Saito Houjou is set to inherit his grandfather’s major corporation. First, he must marry Akane Sakuramori, the girl he despises the most, and who hates him just as much. The two are determined to keep their unexpected marriage a secret from their classmates. But as they begin their newlywed life, the distance between them starts to close.

(Source: Crunchyroll, edited)