When I found out that there is a possibility to import a MMD model into Blender and make an animation here, I got stucked. I am a begginer and wanted to try a simple animation of walking. I was folowing some video tutorial on YT step by step but when it got in the point you have to flip the position of your bones to the other half of your model body, it just keeps messing up. The bones are in really wierd ankles and are right the opposite way they should. Somewhere I found that the issue might be wrong named bones but since this is a MMD model (right from MMD program) the character should be rigged and the bones named just right.
Here is a picture what it does when I copy the position of the bones (ctrl+c) and try to apply it on the other ones (shift+ctrl+v):