The Japanese word for choke is shime. That's just a term for chokes and strangles in general. Shihan apparently knows quite a few and they all have names. It was the focus of last night's class.
Here, from another style, is a video showing approximately what we were working on with hadaka jime. The entry we learned was different, but this is what I could find.
The last technique shown in the video is not anything we worked on, but starting at 2:15 there is a choke from the rear after the uke has already been taken to the ground. I almost didn't post this video because I am concerned that part might give someone I know some new ideas.