Shonan Junai Gumi! 5 Forever Onibaku

Follows the adventures of Eikichi Onizuka and Ryuji Danma together known as Oni-Baku, Shonan's strongest fighting duo as they try to lose their virginities, while trying to survive through high-school. The series is considered the prequel to GTO showing Onizuka as a teenager before he became the world's greatest teacher.