Tensei Shitara Hime Datta node Dansou Joshi Kiwamete Saikyou Mahou Tsukai Mezasuwa.

Isabella, a princess protected within a magical kingdom, is reincarnated as Ikuto, an ordinary high school boy. He is delighted to discover that he can use magic, but learns that women are forbidden from practicing it in this world. Unwilling to abandon his ambition, Ikuto decides at sixteen to leave the castle and pursue his dream of becoming a magician. His journey brings together a handsome wizard with unusual circumstances and a princess who dresses as a boy, though she is secretly a high school student.