This is a series you either love it or hate it.
I used to love this series but after watching other series it made me realise that it just isn't a great show.
the cast is nice but the plot doesn't help at all. It has an unharnessed potential.

The famous cliché of the best friends that fall in love after an adventurous night had everything to be perfect but the repetitive plot that circles around the same situation makes it really tiring.

It has a nice amount of hot scenes that are really well made, but the characters just ain't it. It could have being really good it's just that the potential wasn't well spent.

Knock is a selfish bastard that plays with Korns feelings an grasps onto a futureless relationship with his girlfriend, Korn is is an idiot that lets Knock play with him and then go back to the creature he calls gf, Plern Pleng is a character made just for the reason of ruining the main couple, the doctor is really gross an Farm is really dumb, Prim/pring(Farm's gf that i have no idea of what is called) is just an unecessary character, Korn's sister is awful, the friend of them that likes her is a nice character that is not really doing nothing relevant, Fai is kinda nice, and Yihwa is the only reason a lot of people finish the series. There is no character developmentat all.

Despite all of that I think it is worth to watch at least once if you have the time because you might enjoy it.