Boku wa Mahou Shoujo (♂) ni Koi wo Shita

The year is 20XX. An evil organization suddenly appears in Tokyo, plotting to take over the world. Only the invincible magical girl can defeat and purify them! This magical girl is immensely popular among the people, but her true identity is... an ordinary male high school student, Ryou! Ryou has feelings for his childhood friend Kana, but it turns out that Kana likes Kise, the most popular boy in school. Moreover, when Ryou helps Kise during magical girl activities, Kise is captivated by his magical girl form. What will become of this love that begins without the knowledge that the magical girl is actually a boy?

(Source: Flower Comics, translated)