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.

Arranged/contract marriage between the FL and the ML who is either a general or the son of a general turns to love. Both are mostly light dramas with a sweet relationship between the main couple.

FL ends up in a forced or contract marriage with the ML who is either a general or the son of a general. The marriage ends up growing into love. Both are light romantic dramas with happy endings.

FL ends up in another girl's body, married to royal ML who is cold toward her at first. SFL is a jealous concubine scheming to get rid of her. At some point the FL gets banished to the distant palace where the ex-concubines live.

The FL ends up in a different world from her own and meets the ML who initially tries to kill her but then slowly falls in love with her. Both are mostly light and fun dramas.

The FLs in both have a false/someone else's identity and find themselves married to the ML. The FL dislikes the ML at first and the ML is initially cold and wants to get rid of her but slowly falls in love with her.

The FL is in a different time or body. The main couple dislikes each other at first and the FL is more interested in another guy/other men. Both have similar vibes and tone.

Both are light dramas with the FL having a fake/someone else's identity. Both MLs are cold and threatening toward the FL at first but gradually fall in love with her.

The FL is in a different place or body. The ML dislikes her/wants to harm her at first but gradually falls for her. Both are mostly light and fluffy dramas with a similar feel.