I was sent the images below from a female friend of mine, mainly because she knew what I would comment on *specifically*. Neither I nor her know the Manga show that the characters below are from, but their names are Yoko (the busty chick) and Boota (the little furball in her cleavage.
Now, I'm willing to impart that ol' "suspension of disbelief" to accept that a little furball could live in her cleavage without leaving poop or urine in her bra. That's just cartoons, and it's how you dudes' strange little horny minds work. But, there is a problem in the image that follows below.
Okay, you see those two images. Now check out this one:
See the problem here? Well, I'll explain it for you: Boota is not in Yoko's cleavage! Don't think so? Look again. Note that you can see the space between Yoko's boobs at the bottom of her bra. That span is where Boota should be. In other words, that bra is connected at the bottom only by that thin red strap, and does not form a pocket for Boota to be staying in. In order for Boota to be residing in her bra, there needs to be fabric spanning that cleavage to form that hamster-holding pocket.
So... just where is it that Boota is emerging from, if not Yoko's cleavage? It looks like he's emerging from her sternum, a la those Alien movies! Somehow, Boota is literally burrowing into her chest! Wouldn't that hurt, you think? Unless Yoko has some super power that allows critters to burrow into her body, but that's just creepy.
Anyway, that's my take. Sorry if I burst any of you guys' bubbles there... :-P