Both have a same-sex romance, manner of death is a bl, Petrichor is a gl. Both have the same screenwriter. One of the leads in both series is a doctor. Both series are about investigation of death/murder combined with some romance.

Both are a lesbian romance. Both have the same actors. Both deal with the relationship of a woman that is a "commoner" and a woman from a rich/royal family. Both have a forced marriage to a man. Both have a happy ending.