Several things I want you to note here:
Yusei, Crow, Kiryu and Jack apparently used to be members of the Batman Boy Scouts.
Their uniforms were terrible.
Turning into a dark signer obviously has made Kiryu prone to laughter-related seizures.
Yusei, Crow, Kiryu and Jack don't actually age, or else they're all a lot older than we were previously led to believe. How many things did they do while looking that exact age?
I suppose I can forgive them if they were, say, fifteen when they did the Batman Boy Scout thing, and they're like, eighteen or nineteen now. But for Yugi's sake. Characters in Yugioh used to look differenter than that at differenter ages!!!
Anyway, believe it or not I'm horribly amused, especially at the whole ninja scatter thing toward the beginning of the clip.