If you were looking for the trope, that's called Determinator now.
High school student Kiri Minase looks like a supermodel, often acts like a fairy tale prince, and is wildly popular with the local schoolgirls- several confess their love every week. Problem is, Kiri is a (straight) girl. She hates having inherited her model dad's looks, and has tried all her life to become girlier (which hasn't worked too well). She only acts princely to girls who confess their love because she knows what unrequited love is like and doesn't want to hurt them- otherwise, she acts like a normal teen girl.
She's in love with her neighbor, the effeminate Tohya Enishi, and has been ever since they were young. One day, Tohya decides he wants to become a male model with Kiri's mother's agency. In order to stay close to him, Kiri decides to become a model, too... But there's a catch. Her mother will only hire her as a male model, going by the alias "Tatsuki."
And then, people start falling in love with Kiri, Tatsuki, or sometimes both at once... Drama, romance, and of course, much Hilarity Ensues.
Also known as "NebaGiba!," it was written and illustrated by Hiromu Mutou, and ran in Hana to Yume from 1999 to 2007, spanning 13 volume. Only 8 volumes have been translated by Tokyopop before their shutdown in 2011.
This manga provides examples of:
- A-Cup Angst: Kiri, but only briefly, since a flat chest is much easier to bind down while she's being Tatsuki.
- Attractive Bent-Gender: Possibly justified, as Kiri looks like a Bishounen whether she's crossdressing or not, thanks to genetics.
- Becoming the Mask: Characters who know about Kiri and Tatsuki tend to warn her periodically that if she's not careful, her life as Tatsuki will take over her life as Kiri.
- Driven to Suicide: Kiri threatens to leap off the roof of her school whenever she has a nasty realization, and Natsu yanks her back. Played for comedy.
- Gender-Blender Name: Makoto is a gender-ambiguous name, and Kiri thinks she's a guy until she sees her on TV.
- I Want My Beloved to Be Happy: Akira doesn't mind Kiri and Tohya being together because Tohya makes Kiri happy. (He's not going to just hand her over, though.)
- Knight Templar Big Sister: Tohya's older sister Asaki is very protective of her little brother.
- Love at First Punch: Parodied in a 4-koma. Akira comments that he must be special to Kiri, since he's the only one she's violent towards. She wonders why that makes him happy...
- Love Triangle: Kiri has feelings for both Tohya and Akira, both of whom are also in love with her.
- Masculine Girl, Feminine Boy: Kiri is more masculine and Tohya is more feminine. As the series progresses and they get more comfortable with themselves, this starts to switch somewhat.
- Noodle Incident: The "blackmail" photo of Kiri's father in drag. "Oh yeah, I remember that, I did that for a festival when I was a high school student."
