Both dramas feature a FL that is jaded because of her paranormal ability.
Both dramas have a mix of humour, romance and cynicism.

Although the setting is different, both are BLs and in both one of the MLs is a sweet psycho.
In both dramas thet wto MLs complement each other in temperament and strengths.

Both are romantic comedies with a couple from two different worlds.
In both dramas the ML is stronger than the FL and has beastly traits.

For the viewers who get a kick out of watching badly done dramas, they are both such train wrecks that it's amusing to watch.

The setting and tone are different, but both dramas deal with an age gap and have the two leads dealing with the change in their dynamics from friendship to romance, although in Hidden Love the romance aspect is stronger.
In both dramas the younger girl has the ability to act as an equal and teach her older partner a few life lessons, despite the initial difference in age and status.

They both feature a few investigator in surrounded by men who think they know best, both have a funny beginning that turns more serious as the drama progresses.

The story isn't similar but both of them have the same relaxed vibe with two main character who know how to communicate like grown-ups.

They are both based on the same novel, each country gave their version a different tone.
I think it's always interesting for the viewers to watch both and decide the pros and cons of both.

Both dramas have a group of friends trying to right wrongs and solve mysteries.
Both dramas reverse the usual gender roles with male leads that use their brains instead of their fists and female leads who are good at fighting.

In both historical dramas Chen Xiao plays a similar character: a smart and strong man falling for a strong woman, while their pasts put their future in danger.

Both are BLs with a slightly supernatural element of sensory loss that's connected to their "other half".

There is something very similar in the aesthetics of the two BL dramas. They both use harsh light and deep shadows to symbolise a problematic states of mind. Both dramas have a main character with an unresolved past that gets in the way of a new love.