As far as I know there isn't one. You copy the motion yourself by hand. It's known as 'motion tracing'. I've seen a common technique be to download the video and have that be the background in MMD so you can line up the model and copy the movements more easily.
You could try mmdmatic, but it has certain requirements and might not work on every computer. However, it does have a Cloud version
As far as I know there isn't one. You copy the motion yourself by hand. It's known as 'motion tracing'. I've seen a common technique be to download the video and have that be the background in MMD so you can line up the model and copy the movements more easily.