The actors of 'School 2013' have displayed their close friendship that endures even outside the filming set!

On January 3rd, Choi Chang Yup uploaded the pictures above onto his Twitter and along with it wrote, "At Jonghyun-hyung's place."

Kim Jong Hyun also wrote on his Twitter saying, "My friends from classroom 2 came over today. Ultra, best, great, giant, super, best feeling. I have to go to school tomorrow so I should sleep early tonight," referring to his co-stars and returning to filming for 'School 2013'.

The picture taken shows the actors of the trending drama gathered around and having a good time. Their apparent closeness had viewers of the show smiling.

On another note, 'School 2013' depicts problems that show up in school environments to bring attention to  some of the issues that may be going unnoticed.