I'm a Pet At Dali Temple (2018)

They are similar because both dramas are fantasy romance and in both cat is turning into human especially into woman.

After an accident, the soul of a 21 century woman traveling back into another time/paralele universe into the body of a dying woman.

Both are about the relationship between a cat/human and a human.
............................................................................................

Both dramas have a poisoned ML and a FL from another time who is the only one who can cure/ease his condition.

Both are mostly fluffy dramas with a poisoned ML who can only be saved/cured by the FL who comes from another world.

Both are short, fluffy historical set dramas with a poisoned ML who can be helped/cured by the FL.
..................................................

Both are fluffy dramas with a modern day FL ending up in the past, falling in love with the historical ML.

Historical set, breezy dramas. In both the ML has been poisoned (although it doesn't affect his health, only his senses in YSMD), and the FL is the only one who can ease or cure his condition which results in the two living/working together.

Both are about the relationship between one of the leads who is human, and the other lead who is a cat/human shapeshifter.

FL travels from modern day to historical setting, meets and falls in love with ML. Both are fluffy, light dramas with a quirky and adorable FL.

Both are about a cat in human form.
..................................................................

Cat/human shapeshifting lead (ML vs. FL) meets human ML in cat form and ends up living with him.
.................................

Lighter tone, short, and enjoyable dramas with an adorable FL who travels from modern times to a historical setting, meets the ML and falls in love with him.

FL is a shapeshifting cat/human who meets and ends up living with the human ML. Both dramas have a mostly fluffy feel.

In both dramas the ML has two personalities.
........................................................