Ml has patriotic job serving nation
Both has childhood connection between the FL and ML
Fluffy romance without any rival in later parts

The ML has Patriotic job which serves the nation
Both have similar love stories where they had some story in childhood.

Its similar due to North korean soldier carrying out mission in South korea and different in the plot somewhat as it has a romantic couple development

Its similar cause the ML is somewhat of an anti-villian who kills the bad guys for justice and the FL is a cop trying to catch both the bad guys and the ML