shounen ai or yaoi manga with presented as a bride. Can be a supernatural theme, yakuza, maybe his parents is in debt so he was forced to marry the seme, can be the uke undercovering as a btide to buy some time. I've read I-Ren and that omegaverse yaoi where the uke joins a competition to become the apha's wife and royal fiancé. Oh and I would REALLY prefer if the uke is not head over heels with the seme.
Thank u so much