User blog comment:Xilinoc/Realistic One Piece/@comment-24850639-20150526201609/@comment-10543621-20150527234950

There is of course the fact that the entire world's female population basically enlarged their boobs in general as the Strawhat crew journey throughout the Grandline. Could this *gasp* perhaps be what One Piece truly is??? When Luffy finally finds One Piece, all the woman will have boobs so large the clothings finally fail to keep them in!

But yeah, I think it's pretty obvious Oda has been increasing boob size over the years. Nami is the perfect example. Her appearance in East Blue was no where even considered big boobed.