In both the ML is an animal (bear vs. cat) who appears as a human.
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Both are short dramas in which the FL enters the world of a story and ends up altering the plot, sometimes intentionally. She also ends up falling in love with the villain of the story.

FL is murdered by the ML, returns/enters the world, and must try to change the plot in order to survive. Over time the ML falls in love with her. Both are short fast=paced dramas.

Both are short dramas with the same actor. In both someone enters the world of a story and must change things to survive which leads them into a relationship with the villain.

FL enters a novel and finds herself married to the ML, the villain of the story. She must change the plot in order to insure that her written death doesn't happen, and in the process the couple fall in love.

FL enters the world of a story (novel vs. drama), initially views the ML as the villain. The ML distrusts her at first but slowly falls in love with her.

Both are mostly light dramas with a similar feel. The FL is from another world and arrives in the historical/other one in the body of an "ugly" maid vs. "ugly" concubine. ML is royal in both.

ML is of higher status than FL. ML is a scholar, more weak/gentle type. FL solves problems within the family once she marries the ML, including helping his older brother's wife in her unhappy marriage. Similar vibes and tone despite being different in length.

FL has a contract relationship with the ML (pretending to be his sister vs. being his wife for a short while) which is to benefit the ML's father in some way. Both are very short and sweet dramas with happy endings.

Contract/forced marriage between the mains which isn't meant to last blossoms into real love. Both featuring conniving SFL(s) who just will not quit.

Fake/forced marriage between the leads turns into love.
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Lower class FL accidentally ends up in a marriage with the ML (contract vs. switch) but ends up falling in love. Both have lovable bandit characters (FL and her "brother" in HOML, SML in TOD). Both dramas are light and romantic with very happy endings.