1. ML was heartbroken due to FL's demise/ departure & kept waiting for her.
2. FL reincarnated as a boy & returned to ML.

In both-
1. FL & ML were soulmates in their past life.
2. FL is immortal/couldn't die & currently waiting for ML.
3. ML doesn't remember about her.

In both -
1. FL couldn't end her life because of her past mistakes & currently waiting for ML in a shop/hotel & guides souls.
2. FL is the CEO/owner while ML is her subordinate

In both -
1. FL is dominant & leader of sect/ general of kingdom
2. ML is submissive & her bodyguard/ matrilocal husband
3. ML has hidden agenda but falls in love with her

Both are about -
1. Time travelling & setting things right to change the final outcome.
2. Adapted from web novels & well written, executed

In both dramas -
1. FL makes the first move, but ML loves her deeply too
2. ML is heir of his family's company
3. Their first meeting (in present) was in a bar
4. Business themed & includes past encounters

In both dramas -
1. ML is a prince & he behaves like a innocent child to hide his ability
2. FL is a trained fighter & wants revenge
3. FL has a tendency to run away from ML

In Unknown they're brothers (not blood related) & here they're Uncle-nephew (not blood related) & both are Taiwanese BL