Ex-Formula 2 driver Fukuzumi posted his quickest time of the day during the two-hour morning session of 1m21.687s to go 0.422s clear of nearest rival Toshiki Oyu for Nakajima Racing.
However, Oyu’s best time from Tuesday’s opening day of running, a 1m21.371s, stood as the fastest of the test overall.
Fukuzumi and Oyu’s morning times put them at the top of the standings for the day, as Ryo Hirakawa (Impul Toyota) topped the afternoon session on a 1m22.148s to slot into third overall.
Ritomo Miyata (TOM’S) was fourth-fastest and top rookie, leading the afternoon session until Hirakawa set a late improvement with just six minutes left on the clock.
Tomoki Nojiri completed the top five for Honda squad Mugen after setting the third-fastest time for the morning session.
Next up were three afternoon improvers, with Kazuki Nakajima sixth for TOM’S ahead of Sho Tsuboi (Inging) and Naoki Yamamoto, who remained some way off the pace of his Nakajima Racing teammate Oyu in eighth.
Kazuko Kotaka, replacing the absent Kamui Kobayashi at KCMG, was ninth overall ahead of Dandelion super-sub Ukyo Sasahara, both drivers setting their best efforts in the morning.
After causing two red flags yesterday, Yuhi Sekiguchi (Impul) was the cause of another interruption during the morning session with a little over 10 minutes left on the clock, coasting to a halt at the pitlane entry after his kill-switch was inadvertently activated.
That brought the morning session to an early end, and the afternoon session was extended by 10 minutes as a result, with Sekiguchi ending up 11th-fastest.
Tatiana Calderon (Drago Corse) stopped on track earlier in the morning, causing the first red flag of the day, the cause of which was traced to a loose seal that led to a transmission leak.
The Colombian racer propped up the timesheets in 18th place, a little under two seconds off the pace.
Fuji testing times: