NTR Kishi 1

Knight-in-training Coleus is overjoyed when his childhood friend Artel returns to his training school as his new instructor, now a beautiful and celebrated knight.

But when the jealous rival instructor Rock gets hold of a grimoire of forbidden control magic, he turns it on Artel, stripping away her will to defile her body, take her virginity before Coleus's eyes, and corrupt the proud knightess into his obedient plaything.