Fujisawa was born and raised in Hokkaido and started drawing as a child. Fujisawa originally wanted to be in animation but decided manga would give him more freedom. He based Shonan Juni Gumi at a seaside location after growing up inland. At the age of 17 he moved to Tokyo by himself to become a manga artist. He wrote Science Fiction Doujinshi and submitted them to publishers. He is a fan of Initial D and was inspired by Akira.
Much of Fujisawa's output is built around the characters of Eikichi Onizuka and Ryuji Danma. The two first appeared together in Shonan Junai Gumi as high school aged Bōsōzoku in Shonan. The series was a hit and after its conclusion Fujisawa drew two short stories entitled Bad Company, telling the tales about how the two met and became friends. This was followed by the international hit Great Teacher Onizuka, which follows Eikichi as he becomes a teacher and takes care of a class. In this series Ryuji only appears occasionally, as do a couple of other characters from Shonan Junai Gumi. The two characters were then left alone for several years until Fujisawa picked up the story again for the Great Teacher Onizuka spin-off GTO Shonan 14 Days in which Eikichi returns to Shonan. A year after the end of Shonan 14 days, Fujisawa created the short-lived GT-R, which focuses on the exploits of Ryuji rather than Eikichi.