Gakuen Prince

Gakuen Prince (学園王子, Gakuen Ouji) is a manga by Jun Yuzuki. It ran in the Bessatsu Friend manga magazine from December 2006 to July 2011, and is complete in twelve volumes. Kodansha Comics has licensed it for digital release in English.

Plot
Joshi High is an elite school that most girls in Japan only dream of attending. Then one day everything changes–the all-girl school goes coed. There’s just one catch: The girls outnumber the boys. So begins a wild, no-holds-barred competition for the boys of the school. Which smart and independent-minded girl will rise above the fray?

Official
Official English site