I really like this kind of plot! :-D
I tried to match your description:
She is a North Korean Spy and approach him in order to complet her mission (Rom/Com)
https://mydramalist.com/2389-myung-wol-the-spy
Because she look like the already dead girlfriend of a gangster boss she gets sucked into this world and has to do some things to survice (Action / Romance)
https://mydramalist.com/19968-karn-la-krang-neungnai-hua-jai
A General falls for a woman at first sign, but she is the strategic general of the enemies and the only one who could eventually defeat him (Wauxia / Action / Rom)
https://mydramalist.com/19028-general-and-i
The FL get forced disguising as the wife of someone in order to save her live but the man she has to deceive all the time slowly gain her heart (Suspense / Drama / Rom)
https://mydramalist.com/13388-mask
The female lead made a deal with a guy so that he will safe her. While he falls for her she never loses her track to higher targets (Action/ Melodrama/ Rom)
https://mydramalist.com/14655-yong-pal
The FL gets close to the ML in order to take revenge... but while he becomes her mentor she develops feelings for him but will she decide to be loyal in the end? (Historical / Rom)
https://mydramalist.com/19464-princess-agents
The FL want to take revenge but the ML who admires her will do everything to stop her (the conflict is on both sides as she secretly likes him back) (Revenge / Romance)
https://mydramalist.com/16289-fai-lang-fai
After her brother-in-law died and her twin sister gets badly injured the FL takes the place of her sister to investigate the possible culprits in the family. The ML lead doesn't trust her at all but can not help but feel attracted while time is passing by
https://mydramalist.com/27416-khun-mae-suam-roy