One manga at mangatensei.net,Chapter- 71.

High schooler Jenny You is living a dream. In the public eye, she is a delicate princess, a successful pop star, but in real life, she's a rebellious beauty ostracized by her female schoolmates. She and her classmate, Eumpa Won (One), seem to have nothing in common on the surface. Eumpa is a quiet boy, ignorant of the pop culture that has enchanted most of his peers. Having spent his childhood as a depressed prodigy in the United States, he has now resolved to lead a normal life as a regular boy. He likes a cute-but-average-looking girl, Young-ju Chae. Young-ju takes him to a pop concert, and Eumpa is exposed to Jenny's music for the first time. Meanwhile, umpa's resolution to live a normal life is challenged when his music teacher steals the young man's music and attempts to pass it off as his own... So begins the story of One...