Kirikago-hime to Mahoutsukai

Deep in the forest, in a tower shrouded in mist, there lives a reclusive wizard by the name of Nebelhaut. When he happens across a beautiful fairy who's being held captive and made a public spectacle, he knows he has to take her with him. He names the creature Sti and orders her to call him his master, but her heart remains closed to him. But as time goes on, she sees a different side of him—a side that's both caring and awkward. The distance between the eccentric wizard and strong-willed fairy grows shorter day by day!

(Source: Kodansha USA)