I don’t care what other people say - in my head canon, Ryuko has this huge crush on Mikisugi Aikuro.
She’s very much in denial of such absurd feelings for him, since he’s her teacher and she just kind of met him. He also treats her like a kid (i.e. the “you’re a seventeen year old kid who doesn’t know how to take a joke, I see” comment from Aikuro), which doesn’t actually help.
On the topic of she feels better when she’s talking to Mako - of course, she would. Chicks over dicks, at any time of the day. Take in consideration that she doesn’t exactly trust him, since he’s not exactly being totally honest with her - still, she couldn’t help but blush whenever he’s around.