Sambo leg locks from Japan?

I'm not afraid to admit my knowledge of grappling(or any martial art for that matter) is probably lacking more than I'd like to think. I'm also not afraid to admit that one area I fall short in is leg locks. I do not know anything about them other than to tap if I get caught in one and not to try to roll out of one unless you know what you're doing, which I don't. And it's videos like this that show me how much more I have to learn. Now I'm going to watch the strikeforce I missed while out of town that everyone(literally even my mother) has told me to watch.
Keep rolling on grapplers.