Sakuya is mean on the court. Her ability to stop time makes it hard to get a good one on her. Also she is known to cheat and send multiple balls at once.
Top Tip: Try not to drool think she isn't wearing any underwear.
There is more than enough of her ass exposed to know 100% that she isn't wearing panties. In fact, the artist himself tagged the image "はいてない" (not "はいてない？") on the pixiv page.
