Best way I can desrcibe this is if Nagatoro became an absolute super-sadist like say, Sougo from Gintama but with almost none of the nuances. There are some good chapters here and there but man, she doesn't need to go through such lengths to tourment him.
@crimony I honestly think the feeling's mutual. I mean, Ryo addressed her as his bro's friend and tbh I'd also get sad if I were to be addressed like that. It feels so distant. Like you're not actually his friend.
Also [spoiler][/chapter 51 is really special]