I'd say that's a tie, more or less. Kuro's immensely more prone to outbreaks of Foot-In-Mouthitis compounded by recurrent Digging Yourself Deeper Syndrome whereas Yuri is wont to get passive-aggressively rude af typically followed by abruptly bailing from the situation without so much an "excuse me".
@katewarner - I think she got her "pretty pink color" eyeful (and other related details) during the class trip actually. She was in the open-air bath at the same time as Nemo and blatantly took a closer look when the latter climbed out...
Crocodylus kurokis: lurks in hot springs, waiting for eyecandy to appear :P
^ You're right! I'm really worried after the last chapter. It's No More Nice Girl for Nemo. Tomoko has crosshairs on her. But to mess with Tomoko is to mess with Asuka. What a series.