Bumrushing someone unprepared will always win, even against a trained martial artist lol
I don't think Hino really meant she wanted to go to P.E. to protect Koguma. That was a pretty obvious excuse. She was just caught by Koguma's cuteness and wanted to go along with her wishes.
Aside from Hino's obvious preferences, I wanna point out that Koguma does constantly praise Hino's looks too. These two are so gay.