Kawaii Hito

Kenzaki, a female yankee, has a crush on Nakajima, a boy who gets constantly teased in class. One day, she saves him from his bullies, bringing the two to become closer with one another. Shortly after, Kenzaki notices a girl who looks a lot like Nakajima. However, it turns out that it is indeed Nakajima crossdressing! (Source: Kadokawa, translated)