Ochikobore Majo to Koi wo Shiranai Tensai Majutsushi

The world of magic supremacy. In this world, the stronger the magic power, the closer the hair color to the color of moonlight, and the weaker the magic power, the hair color is darker and more subdued. Ashley, with her sooty, brick-red hair, is excellent at writing and manipulating magic, but her magic power is so weak that she could not become the mage of her dreams. In the end, Ashley is granted temporary mage status by her mentor, the Secretary of the Ministry of Magic Education, but in exchange she is asked to educate an imprisoned young man with immense magical power that no one with magical power can even touch...?! A young man who has lived a solitary life and a mage with a reason. This is the beginning of a love story full of lies and secrets. (Source: Ichijinsha, translated)