In this dramas ML /FL are best NIS agents in their fields
He/She lost someone close to them
Related to whole mystery and conspiracy
both include a lot of action, crimes and investigations

Both dramas ML are best agents in their fields
He lost someone close to him
Related to whole mystery and conspiracy
both include a lot of action, crimes and investigations

Both dramas ML are best agents in their fields
He lost someone close to him
Related to whole mystery and conspiracy
both include a lot of action, crimes and investigations

Both Dramas ML are top elite agent in their field (TV - NIS agent , K2 - Soldier)
Due to some reasons ML gets rogue/disappeared due to conspiracy
Full of Action, Mystery, Thriller which will keep you on the edge to watch what happens next
If you like the veil I suggest to watch The K2 as well

The plot is not similar but both dramas ML are elite NIS agents
Both dramas will give the Action, Thriller vibes
Both dramas ML lost someone close to him
Related to whole mystery and conspiracy
both include a lot of action, crimes and investigations

The plot is not similar but both dramas ML are elite agents in their fields
Both dramas are Action pack , thriller & many more (only in 3 Days he is an elite bodyguard agent to protect the President of Korea)
Both dramas will give the Action, Thriller vibes

Both dramas ML are NIS agents (except TFP due to a trauma he left & became a priest)
Both dramas contains Action pack , thriller
I suggest to watch both dramas as they will keep you on the edge at every episodes

The plot is not similar but both dramas ML are NIS best agent (except MTM he becomes a ghost agent to do missions)
Both dramas are Action pack , thriller & many more (only in MTM he becomes an undercover agent by disguising himself as an Action Celebrity Stars Bodyguard to do the mission)
I suggest to watch both dramas as they will keep you on the edge at every episodes

I will say that even the plot is not similar but it will give you the penthouse vibes
Rich people will do anything for their greed
Upper class parents especially mothers will try their best even illegally for classy education for their children.
Both of these dramas will keep you on the edge its a one time watch (as penthouse has 3 seasons so it has more episodes to understand the plot)

Both dramas are about solving cases by finding the cause or disease (DF - Psychology , GQ - Rare diseases during Autopsy)
Both are of the same channel OCN
Both dramas have suspense, thriller & serial killer in between
Both ML has a past which they don't share to others easily
Both ML are well known genius at very young age in their professional fields
If you liked Dr Frost I strongly suggest to watch God's Quiz which has total 5 Season episodes

Both dramas are similar as they have police detectives & their struggle to fight against crime
This drama is also gives the same vibes of police investigation, procedures & other circumstances they face against the powerful peoples

Both dramas are similar as they have police detectives & their struggle to fight against crime
This drama is also gives the same vibes of police investigation, procedures etc