Lee Jong Suk plays a young many with an attitude that seems he doesn't even care about swimming. Pressure can take enjoyment out of anything. Seo In Guk is a young man that has basically nothing and needs to work for everything he gets. The movie does a good job with the bromance, showing how they become better once they become friends.

Kwan Yu Ri - I felt that her part was poorly written and not very well acted, if I'm honest. I couldn't see how either of them could fall in love with her and she just seemed too shallow.

We get to see Lee Jong Suk's charm, which is always a bonus.
Seo In Guk with physical comedy and over-the-top use of his face and his hands, just wonderful. He does goofy well (as further evidenced by Shopping King Louie and King of High School).

I enjoyed the swimming scenes, as well as the rare opportunity for an overbearing parent to turn around.