I loaded the model into MMD, there were no issues until I loaded a pre-made motion data. For some reason, the motion data moves the bone for the breast. I opened the model again in pmx and looked at the bones. There's some kind of error on number 140, 141, 143, 144, and 154 (the breast bones for the dress). I will have to take some time to google it after I wake up.
-Update-
I googled around and couldn't find any solution, so I deleted the dress breast bones and re-rigged them to the unrigged breast bones.