While travelling in Japan a few years ago, I picked up a few copies of BJJ spirits magazines and they had articles on Bonsai-Jiu Jitsu and Roberto Satoshi Souza (a purple belt at the time) and his black belt brother + a few fights of them on DVD here and there. Souza had a very fast paced style and utilised the reverse de la riva guard a lot which caught my eye. Later I saw a lot of sparring sessions with Mendes brothers' and other grappling stars at Bonsai academy on DVDs produced by Bull Terrier.
Roberto got his black belt a while ago, and surprised more or less everybody by getting the gold medal in this year's Europeans. He also did it by beating both Michael Langhi and JT Torres, 2 of the best lightweights in the world.