Rakudai Kishi no Cavalry

In a world where people can turn their souls into weapons, Kurogane Ikki is a student training to become a Mage-Knight despite having little magical talent. Branded the “Worst One” and forced to repeat a year, he faces a new school rule requiring compatible knights to share rooms and train together throughout their studies. Ikki is paired with Stella Vermillion, a princess from another country and a rare Rank A magical genius. After he accidentally walks in on her changing, a misunderstanding leads to a duel. The loser must submit to the winner, and the two are left to live and train together. How their relationship develops remains uncertain.