Koochan was a regular student who was really decent and concentrated on studies, until one day one event made a change in his life. He fought against one of the scariest boys in his class, and this fight made him feel free. From that point on he fights bad guys from other schools and gets involved in a lot of problems.
This story goes through the high school years of Koochan and his friends. It revolves around friendship, school gangs and Koochan's love; a very cute girl from his class called Yamada.