Hanazakari no Kimitachi e (Hana-Kimi: For You in Full Blossom) - Nakajo, Hisaya

Japanese-American track-and-field star Mizuki has gotten herself to transfer to a high school in Japan...but not just any school! To be close to her idol, high jumper Izumi Sano, she's going to an all-guys' high school...and disguising herself as a boy! But as fate would have it, they're more than classmates...they're roommates! Now, Mizuki must keep her secret in the classroom, the locker room, and her own bedroom. And her classmates—and the school nurse—must cope with a new transfer student who may make them question their own orientation...

(Source: VIZ Media)
Included one-shots:
Volume 1: Natsu no Ori (The Cage of Summer)
Volume 4: Kawaki no Tsuki (The Thirsty Moon)

Hanazakari no Kimitachi e was published in English as Hana-Kimi by VIZ Media from September 7, 2004 to April 15, 2008. A 3-in-1 omnibus edition was also released from March 6, 2012 to April 1, 2014, wherein the final volume also included Hanazakari no Kimitachi e: After School.