there were 3 shows this season with the same premise of kids fight for some reason related to school, main character extremely skilled with sword and has a fiery, red headed companion to help lead him to victory... ;-;

Rakudai Kishi no Cavalry
Gakusen Toshi Asterisk
Taimadou Gakuen 35 Shiken Shoutai.

google image each if you are a bit fuzzy on the characters