Both have a FL in a entertainment/fashion industry (makeup and livestreaming vs. singer and later clothing designer). MLs are cold at first then very doting when they fall on love. The secondary couples are very similar in both shows with a softer male who chases her vs. colder more distant female who pushes him away at first.
Both dramas involve a rich ML who needs to marry a woman to appease his ill grandparent who raised him and is his only relative. He enters into a contract marriage with the FL who has swapped places with his original contract marriage fiancée, her identical twin. The ML and the replacement bride end up falling in love.