Super Junior Siwon (Choi Si Won) took the lead on August 18 in Hong Kong to do the ALS Ice Bucket Challenge. He then challenged three friends. Guess who responded almost immediately? Here's the video.

Siwon posted the video to his Instagram account and tweeted:

It was fun. now i nominate @leedonghae@eunhyukee44 and sungil park. good luck D&E! :^)

His fellow Super Junior members Donghae and Eunhyuk immediately responded with this video:

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BONUS video: Here's a longer video taken by a fan in Hong Kong that showed Siwon before and after the bucket dump. Watch him (and his pretty blue shirt) from a different angle.

With more than 4 million followers on his Twitter account, Siwon is Korea's most followed person on Twitter, and he can be enormously influential when he takes on a worthy cause. Thank you, Siwon, for supporting the ALS Ice Bucket Challenge.

Visit the ALS Association's official site to learn more about ALS, commonly known as "Lou Gehrig's Disease."

Also: Watch Jo In Sung's Ice Bucket Challenge