Can the Grand Duke and the Marquis be Friends?

Obet has no idea what she signed up for when she attends the prince's oath ceremony disguised as her sick twin brother. Before she can make a good impression on the prince, a snooty young lord pokes fun at her, and the two of them spend the day bickering with each other. As it turns out, the lord is none other than Hinn, the son of the grand duke. To make matters worse, he instantly recognizes Obet when he visits her estate! Once he threatens to reveal what she did and bring shame to her family, she has no choice but to be nice to him. It's easy enough to avoid him at first, but this becomes harder when they start attending the same academy. Will Obet be able to keep Hinn from exposing her secret, despite the fact that he seems to be on a mission to annoy her 24/7?

(Source: Tappytoon)