I'm still unsure about this. I've watched it several times on Netflix and viki but still having the feeling that the ending was not where it was really to end. It should have shown what happened to Jang Guk and Yu Jun-Su.
Should have explained more on why Yu Jun-Su at 19 was like his own father by getting a girl pregnant at 19 as well.
Should have explained more in detail on the reason why his father was so strict on his uncle Yu Su-Han (otherwise should be known as half brother).
Plus should show the other relationships between:
Kang Ham-cho and Jang Hun.
Yu Su-Han and Park Mu-Hui.
Heo Se-Min and Jang Go-Sun.
Ju Da-Hae and Yu Jun-Seong.
There's just so much that's left unexplained like did Jang Guk and Yu Jun-Su get married? Have kids? Did their moms finally chill out and let them be?

And still trying to understand how Wild chives and soy bean soup has anything to do with the storyline. I get 12yr promise.... but not the other.