Very impressive video. It's interesting to see him use a Russian tie a few times, since it's something I'm not used to seeing in Sumo. It doesn't seem to lead to anything useful in this context, maybe because you can't really attack the legs, or maybe it doesn't work as well when you are generally fighting guys who are significantly larger than you. Although he does seem to use it very effectively as a way of diverting his opponent when they are coming straight at him, especially with the guys who over-commit. A few nice arm drags too, which I'm also not used to seeing in Sumo much. Or are they used, and I haven't just seen enough Sumo? Does anyone if that is the case?
In the book, Dynamic Sumo, there is a technique called katasukashi-throwing an opponent down by grabbing the arm he is thrusting with. I don't know much about sumo, but love to watch it when I get the chance... :0)