Gamo Kunpei was born in 1768 to a merchant family in Ustunomiya, present day Tochigi prefecture. His common name was Isaburo, familiar name Kunzo or Kunpei, pen name Shusei or Shusei-an. Along with Takayama Hikokuro and Hayashi Shihei, he is known as one of the "Three Eccentrics of the Kansei Era."
During the Kansei Era, in the late 18th Century, he researched all of Japan's imperial tombs and compiled the "San-Ryo-Si." This work is now known as one of the pioneering efforts of the Imperial Loyalist Theory.
He later came to Edo, worked on his writings, and died in 1813. On his tombstone, the famed scholar Fujita Yukoku wrote dedications on its four sides. Selected in 1942 as a national historic site.