Tenshi Ja Nai by Takako Shigematsu (amazon)

In elementary school, Hikaru had a brief stint as a child model and as a result was bullied by her classmates. Now that she’s in high school, she wants nothing more than a ordinary life. When her parents move to France, she stays in Japan and enrolls in a boarding school for girls that’s designed to turn out perfect wives and mothers. Hikaru calculates all her responses to her classmates overtures to be as uninteresting as possible. But Hikaru’s plans for an anonymous existence are foiled when she finds out that she’s rooming with teen idol Izumi, who Hikaru meets when she’s fleeing from fans. Izumi leaps a wall and lands on top of Hikaru, leaving a silicon falsie behind.
Izumi is not merely flat-chested, she’s a guy! And he’s determined to make Hikaru keep his secret, so he promptly takes photographs of her topless while she’s sleeping in order to blackmail her into helping out with his masquerade. Izumi’s imperious manner leads him to assume that Hikaru will do whatever he needs. Hikaru capitulates when he blackmails her, not knowing what else to do. She gradually finds herself feeling more sympathetic towards Izumi due to his determination to follow his dream, even though she doesn’t really want to know why he needs to pursue fame and money. Izumi is aided by his stoic bodyguard Yasukuni, who has a job as a janitor at the school.
The artwork is attractive, with clean lines and clear layouts that make the action easy to follow. The plot of Tenshi Ja Nai isn’t particularly innovative as there are more than enough cross-dressing shojo manga out there. Izumi’s personality makes him a little more interesting than the typical shojo hero, and I’m curious to see if Hikaru’s exposure to the world of show business starts bringing her out of her shell. I think I’m going to try to check out at least one more volume before deciding to follow the series or not.