I'm pretty certain that the Japanese have a strict division between the "gravure idol" modeling (non-nude) and the "AV" performers (everything else), at least in terms of contracts. Fuko's rather rough-looking topless shoot was at the beginning of her modeling career, I think, but afterward she became a gravure model exclusively. Only some make the transition later to AV hardcore, so we can but hope.

My avatar is Rio Natsume, a slim and stacked idol who I desperately wish would go nude too, and there's sooo many more of them... Such a shame to disallow even a little toplessness. In the meantime, we can enjoy the beautiful barely-covered boobies.