Best Enemy (2023)

Two male leads with strong bond. Fighting and action for life and death with ancient background. Betrayal and yet protecting each other. Many leads are getting killed. Relating to Military or police background.

Both dramas are set during the Japanese occupation.
Both dramas tell the story of good friends who become enemies due to different backgrounds.
Both male leads work under the Japanese government as undercovers.
Both male leads have multiple identity.
In both dramas, first and second male lead have the same love interest.