Contractual Love (2021)

Both stories start with a contract between the main characters agreeing to be brother and sister. Both are also Chinese historical romantic comedies.

Both are mini dramas in which the ML enters into a contract relationship with the FL with her pretending to be his long lost sister in order to comfort a sick relative (father vs. grandfather). The two then fall in love.

Fake brother-sister relationship between the main couple (in CL both know its not true vs. LBTI where the ML knows its fake and the FL thinks he is her brother at first). Similar vibes of their relationship as well. Both are historical setting (LBTI also has fantasy elements but CL does not).

Both dramas feature contract relationships (siblings vs. marriage) that turn into true love. The FLs are quirky and endearing, the MLs seemingly cold but very warm hearted. Both couples sell skin care products, and both are wrongfully blamed for causing allergies on the people who buy them. Both are light, fluffy historical romances.

Both are mini dramas in which the leads are non blood related siblings who fall in love.
..........................................................

Similar premises for the plot: FL hired by ML to play his long lost younger sister...
Of course there will be complications.

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.

Light historical romance with a little bit of comedy. In both dramas the female lead helps the male lead with his cosmetics shop.

Both are short and sweet historical romance dramas in which the FL ends up entering the ML's family under a false identity, but the two fall in love.

Both are mini dramas with a contract relationship between the main couple.
............................................................

Both are historical mini dramas with a contract relationship (fake siblings vs. marriage) between the main couple. Both are set in cosmetics shops.

Both are mini dramas in which the ML and FL agree to a contract relationship as relatives (brother and sister vs. father and daughter) for the ML's need to please a relative, and while living together they fall in love.

Both dramas are contract relationships that grow into true love between the ML who is rich and the FL who is poor. Both MLs hire the FLs for the sake of their parent/grandparent.