I would consider myself an expert on this subject with at least 20 years of experience in observing the workings of this natural phenomenon, and I even have about 5 years of experience in cultivating my own!
OK here are two Links:
HD Version and Normal Version.
Please don't watch the video all the way through... about 2 seconds will be enough to understand the rest of this post!
Now my experience tells me that the motion of the breasts in this video is NOT NATURAL. Some Japanese programmers need to seriously stop writing / playing games and get out there and observe more real people.
As my hero Absath puts it:
Taking all that into mind I give you today's comic!
Thanks to CAD.