I debated for a while whether to tag this as genderswap or trap before settling on the former, because 1.doesn't look like a trap to me and 2.it's an older image, from before Ryo was revealed as a trap, so I think it's safe to assume the author intended to draw a girl.

she's chubby! awwr =D

It is indeed a female Ryou. The pixiv page lists neither tags nor comments indicating that this was a trap.

Oddly, considering how that top might be girdling 'her' a bit, it could have been the usual trap Ryou.