Become a Magical Girl and Save the World Casually

The protagonist, who was originally living on the Blue Star without a father, mother, or support, was accidentally summoned to a strange planet when he was still in school. When he opened his eyes, he saw that a monster had stuck to his face. When he thought he was about to die, a long black elf floating like a doll appeared. Become a magical girl! Now! The key is that I am a boy. How can this be allowed? Seeing that the monster has discovered itself. I can become a magical girl! Become a magical girl!