Nanami was a former student of Tokyo Jujutsu High where he was an underclassman of Satoru Gojo and Suguru Geto. Nanami initially left Jujutsu High after graduating to become a salaryman, but returned four years later to continue working as a jujutsu sorcerer. While working as a Jujutsu High sorcerer, Nanami was ranked grade 1 and operated primarily out of the Tokyo campus. With Satoru's introduction, he also became a close mentor to Yuji Itadori.