I think both Woojin and Chanhee are awesome characters and partners. The only reason why the girl didn't do well with Chanhee was because in a relationship one of the partners has to be more open and outspoken, more goofy, the person who isn't as proud and would not hesitate to call. She was very hesitant and shy and introvert and Chanhee was also like this , that's why there was a lot of miscommunication. Where as Woojin complimented her personality perfectly as being kinda opposite to her traits. Chanhee found himself that red-haired glasses friend who complimented his personality perfectly so I loved this realistic approach. Me, as a total introvert needs a pushy extrovert to pull me out of my awkwardness.
Goodness, even tho it felt like the story kept going on and on about the same drug cartels, finally we got to see the end and it wasn't as tragic as I was afraid it might be. I hope to see a happy ending for Min Hyuk, that boy deserves to smile fr. Plus that boxer kid.