I really dont know where to start!
The truth is that even if it did broke my heart, i have some complains in terms of plot and screen time of some characters, but this show was really good and really made me realise that friendship is very important.
We know what is going to happen since episode 1 but it really didnt make me cry less, the tears where everywhere when i was watching the last episode (not only the last, i think i cried at least once at every episode, but in the last one i lost control).
The plot is very interesting but i think they could had handle some things better. I think they should had invested more in the friendship rather the relationships between the female leads and their love interests.
The acting was exeptional by everyone and i think that is why i cried so much... It felt too real...
The biggest problem in this show is the lack of fairness in terms of screen time between the main characters...
Mi Jo took why more screen time that she should, leaving Joo Hee far behind, Chan Young had a normal amount of scenes. You cant say that you have three main lead and that its a story about friendship and completly ignore one of them. The way they handle Joo Hee characters really pissed me off, she was no where to be found at times and even if it was mention how she felt left out, they never tried to fix it. Her storyline and her love interest was only shown in the first couple of episodes, after that nothing.
I enjoyed the relationships between the leads and the love interests, i think my favorite is between Chan Young and Jin Seok even if i thought i would hate them together at first, i just couldnt. I think that if Joo Hee and Hyun Joon had more screen time together they would have been my favorites but they didnt had proper set up, they kinda came out of the blue. I dont wanna talk about Mi Jo and Seon Woo, not because they werent cute ( they were) but they were EVERYWHERE.

A nice and heartbreaking story...