Mahou Shoujo ni Yasashii Gal

Ayame Meita, a socially awkward high school boy who dreams of being a hero, sees news about ‘Magical Girl Majeri’ protecting humanity from monsters. As various speculations swirl about the mysterious magical girl, even becoming a topic in his class, Meita finds himself connecting with Shion Anri—a cute but tsundere gal who's completely isolated—all because of ‘Magical Girl Majeri’...!? When he learns the secret behind her loneliness, a heart-pounding, kindness-filled magical life begins!

(Source: Comic Meteor, translated)