I like that description, really goes well with the Tsundere tag.
I suppose this is what happens when you tease Senpai so much that he certainly has no choice other than to 'notice' you and...also do a lot more things to you.
Heh, and even at the end, she can't help but continue to provoke him...Almost as if she actually wants him to go for another round.
"Poke a Sleeping Dragon", as the saying goes? Please don't be overly surprised if one day, the Dragon responds to the poke. Another place, time and artist, what happened there could have gone really ugly, really fast; I will simply take it that, for the purpose of this story, Karin (or at least a part of her) wanted 'Senpai' to make a move on her, as was depicted.