Recently, Super Junior was in Japan for their 'Sawa GO! Hasha GO! Moriagarima SHOW! E.L.F-JAPAN FESTIVAL 2013,' which was held on September 26 and 27 at  Saitama Super Arena.  During their festival, the boys revealed that they would be releasing a new Japanese single called "Blue World" some time in December.

This was also member Heechul's first official activity with Super Junior since he was discharged from the military.  He left a cute, interesting, choppily cut Instagram video of himself backstage.  Near the end, he even startles Kangin with his cute antics, causing the video to end with Kangin pushing his head away humorously. 

Check out his video below and mark your calendar for their new single!

SEE ALSO: Heechul believes the prettiest member of Girls' Generation is...?

[Thanks to everyone who sent this in.]