Read manga: Seikou Gakuen Idol-Gumi!

manga
Summary:

Talentless, shy Tsubasa has just been accepted into the prestigious Seiko Academy. He soon gets mixed up with the most popular kids in school -- and the entertainment world! Forced to join the pop idol group RINX as their lead FEMALE singer, Tsubasa soon finds himself stuck in the middle of a cross-dressing comedy full of mistaken identities, blackmail, and kidnapping!