Xiumin's Birthday Fan Meeting Cam - Water Challenge

I don't know what kind of challenge this is either ㅋㅋㅋ;;;

I don't usually watch challenge videos

There were a lot of challenges I was seeing for the first time ㅋㅋㅋㅋㅋㅋ

I guess I'll have to look for it to keep up with the trend.

Where do you usually watch challenge videos?