It may seem stiff with the foundation frames, but it should be more dynamic when I add some slight leaning with Koharu's torso with each thrust, as well as some eye and mouth flutter.
Also, I said I wanted to complete this within two weeks, but it might be a little ambitious, given how busy I am these next weekends, as well as the weekdays...
Here's hoping I can make some decent progress here and there during the next weekdays!