I was able to find some videos but they're not B.E. but they're really good:
Nami breasts bounce (Movie 7)
This clip from YouTube shows Nami with bigger boobs on the 7th One Piece movie. I think she been with Robin aka "Ms. Sunday" too long.
The other clip is what I'll post now. The video is called Sora no Iro, Mizu no Iro Bounce.
I don't know the name of the anime nut it's really good even though it's short.