The katakana is far from illegible, haha. It says "Shiiru" or Seal, the Japanese term for Stickers in Brawl. I can't really make out the kanji, but if I had to guess, I'd say it was
混用 or こんよう. It seems the most logical choice as the furigana LOOKS kinda like konyou... Eh, it's a longshot at best. But I'm pretty konyou means combine. So a "combination sticker?" But it says that for the other stickers too.
Anyways... I found a link to the original video, and I think it should be added to to the original post:
http://youtube.com/watch?v=pfb2l-iYlRo