Sunflower Vol. 2 (manga)

Kinsei High School is famous for its academic excellence. It is infamous for its 90% gay or bi student population. Kunihisa Imaizumi is a cute, homophobic freshman surrounded by a sea of aggressive, gay men. Unable to deal with the increasingly bold advances of his classmates, he appoints his friend Ryuhei as his "knight in shining armor" to keep his suitors at bay. But Ryuhei feels more like a fox guarding the hen house as he falls more in love with Kunihisa each day. It is only a matter of time before Ryuhei can't keep his growing affection and raging hormones at bay.