This one's very funny, one of those films in which the director and the actors do a dance of comic timing. Hye-jeong Kang is always good but Shin Hyeon-Jun turns out to be a real comic treat. This is an action flick with lots of humor.
Jin-young (Kang) is devastated after a breakup with her long time partner and wants to kill herself, but she wants to do it with flair so she hires a hit man to take her out. Hyun-jun (Shin) thinks he is hired to kill someone else and is surprised to discover Jin-young has slipped herself into the place of his intended target. Yeah, it's an "assassin falls in love with his target" story but the performances of the two leads makes this one a winner. The script is a little chaotic at times, lots of coincidences that challenge a suspension of disbelief, but if you just go with the flow it's a fun ride.
The film's ending unravels instead of tying things up but it's not a deal breaker. In a way, the whole film can be seen as a series of sketches that just parade by instead of building upon one another to form a cohesive whole, and that may be a valid criticism depending on the angle of entry the viewer chooses. Thriller? Romantic Comedy? Action flick? It's all of those, and it's one of the things I like about South Korean cinema. They do mashups, and they do them well, always playing with expectations and throwing in surprises.
If you are a fan of either of the two leads you will enjoy Kiss Me, Kill Me.