Dacon said:
She's wearing a sleeveless top, and a skirt.
Just because the top is, incidentally, sleeveless, does not make it a "sleeveless top." In fact, there's a difference between a "tank top" and a "sleeveless top." Perhaps not in lay terms, but in terms of clothing, there's a difference in strap width. For that matter, there's a difference between a "tank" and a "cami," though most people just call any top without sleeves a tank top.
A sleeveless top simply lacks the sleeves, but the arm holes are still cut as though there would be sleeves, and the neck is the same as it might be on a shirt with sleeves.
This is a "sleeveless" shirt, though the collar isn't necessary.
The arm holes of a tank top are cut inward and they generally have a wider and lower cut neck, so that the strap is only an inch or so thick.
This is a tank top.
Then there's the kind of "tank top" that actually has thin straps like a bra. This is called a camisole, as it resembles the lingerie in style.
This is a camisole top.
None of them traditionally reveal the midriff, so you have to use aditional terminology to imply that.
What Tifa wears is a
sports bra. It's different from just being "a short tank top" because of the elastic band underneath the bust.
Now while her choice of a sports bra isn't all that scandalous—and certainly recommended given her DDD breasts—it's the fact that she wears a miniskirt when much of her combat style involves kicking and backflips that calls her outfit into question.
Since I have to leave for work and won't be here when someone asks, I know these things because I have spent the past year selling women's clothing, swimsuits, and the occasional lingerie, and I have to use this terminology and know exactly what they mean on a daily basis.
And yes, I'd wager that Tifa has something close to DDD, just eyeballing my PlayArts figure. Cup size is determined by measuring the ribcage directly beneath the breasts, then measuring the fullest part of the bust (nipple line), and subtracting the former from the latter. And on Tifa that's quite a difference.