I went in with this movie because of Wi Ha Joon, he is one of my favorite actors and I have a huge crush on him. I had expectations that his movie will be a gritty story about prison and school violence based on the posters and I didn't read any spoilers as well but I was pleasantly surprised to see that this movie was more heartwarming and inspiring. The whole message of the movie is quite simple, "Do not give up, fight harder day by day." and they clearly sent that message across. The plot was nothing new nor fresh but it was enjoyable. The main character, Cha Woo Sol played magnificently by Kim Min Seok was a believable sympathetic character and his character growth was great. Wi Ha Joon as Jung Do Hyun, was a great mentor he didn't appear as much as I hope would've been but he was the main heart of this film especially to the main protagonist. The antagonist Seok Chan was played greatly by Jung Won Chang, even though his whole character arc was just ok, I needed more layers to his character. The other side characters, Sang Yeop (The mature captain) and Ahn Hyun Min were likable but I needed more of them though. The action sequences were well choreographed and the pacing was fast and exciting. I felt like this was an origin film, and based on the comments I red down below there is an upcoming TV series sequel to this, if it ever happens this movie is a great introductory to the characters and story so that the TV series could expand more. Also, the ending cracked me up.