[rizu]

**edit: i just noticed you posted niconico in your original post. But from my observations in japan it was niconico or youtube. End edit**

Try ニコニコ動画 (nico nico douga). It's a Japanese video site. You have to register to use it but it's free. Lots of interesting videos on there. If you can't read Japanese To sign up let me shoot me a pm.