I recommend "The Long-planned Heartbeat" to you. This is a modern romance novel about a wealthy family. The protagonist chose to marry his black-bellied younger brother on the eve of the wedding because his fiancé had married someone else. Although the person she was originally protecting had a change of heart, her guardian was still firm. After a series of interactions and getting along, they had the idea of getting married. In the end, Yui got married. I hope you like this fairy's recommendation. Muah ~😗