Aoki (the guy in yellow tights) is something else, despite his unfortunate choice in garb.
He's a student of Japanese BJJ legend Yuki Nakai, who was made famous in his fight with Rickson Gracie back in '95 after having his eye gouged in his previous match that SAME night. Nakai lost that eye.
Here's an article on him:
http://www.sherdog.com/news/articles.asp?n_id=4814
His attitude reminds me of guys I met in Japan. I can tell you that the average fighter, even guys not competing, are so dedicated. They just train. Period. Everyday. Alot of guys work their normal 9-6 or whatever and just train every single night and weekends. It's rather rare for people to have more than one hobby. In my experience alot of Japanese have one serious interest and sort of develop a lifestyle around it.