There is actually a petite Japanese Dive Instructor here who has four (4) nipples/breast. Although not even in size the position of the extra nipples is 1/2 way between the main breast and armpit. Therefore when she wears a bikini top the outer nipples are exposed. She is wonderful person and is not shy about her extra blessing. When I first noticed her extra nipple, she was on my dive boat as I was driving to the site. She caught me staring over the top of my sunglasses at her right side extra nipple. I got all flustered and looked away while I was thinking *wow that looks just like a nipple* and also (perv. that I am) *I wonder if there is another on the other side* When I had mustered enough courage to look again...she was standing right next to me with both arms raised, providing me with a full view of both spare nipples. She was also smirking! Not shy at all! I don't know if you have ever heard of this phenomenon of "sister nipples" as I was informed they are called. They are actually about 1/3 the size of the main/regular breast and have perfectly formed nipples. No, I do not know if they are "full functional" breast. They look like they could be.