Following success in karting, headlined by the 2010 CIK-FIA Asia Pacific KF2 Championship, Fujinami entered the Formula Challenge Japan in 2012 as a member of the Nissan Driver Development Programme (NDDP).

[citation needed] He helped lead GTNET Motor Sports to consecutive ST-X championships in 2018 and 2019, with overall victories in the Fuji Super TEC 24 Hours in each of these seasons.

He did not receive a full season contract for 2018, but returned to Team Mach as a third driver at the Fuji GT 500 Mile Race.

At the Fuji GT 500 Mile Race, Fujinami, Andre Couto, and Tsubasa Takahashi took the GT300 class win, ending a five-year winless drought for JLOC.

[14] Fujinami then joined Kondo Racing for a private manufacturers test in their GT500 car on 24 January at Suzuka Circuit, with the expectation that he would be named as a GT500 driver for the upcoming season.

[17] On 17 February, the same day that Nissan confirmed Teppei Natori as his replacement at the Kondo Racing GT300 team,[18] Fujinami apologised for the incident through his social media accounts.

Fujinami signed a GT500 reserve driver contract with Nissan for the 2023 season, and was retained at GTNET Motor Sports in the Super Taikyu Series.