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Photos: Japanese F4
The rivalry between Honda and Toyota continued in Japanese F4 this year, and title honours went to the latter
Over 14 races across six rounds, and five circuits, the next generation of Japanese racers did battle in their home country’s Formula 4 championship this year. Honda and Toyota, both now involved in Formula 1 once more as well as powering the cars in Japan’s top-tier Super Formula championship, each backed and ran several drivers and once again it resulted in a title.
After Honda junior Yuto Nomura had took home the crown in 2024, this time Toyota junior Tokiya Suzuki was the champion and while driving for the Toyota Gazoo Racing Driver Challenge Racing School.
The season started at Fuji Speedway on May 1-4 with a triple-header round and a 45-car grid.
Ryo Shirasaki topped the opening qualifying session of the year, setting a 1m45.885s to pip Kageyama Racing team-mate and Porsche Japan junior Itsuki Sato to pole by 0.092 seconds. Toyota junior Kiyoshi Umegaki was the next best driver, 0.427s off pole as 0.066s split third to sixth place. A second covered the top 12, with the slowest driver 5.423s off the pace.
Sunny conditions greeted the paddock for 2025’s first race, and there was drama from the off as Sato started very slowly and Shirasaki lurched forward then stopped.
Suzuki, from fourth on the grid, took the lead ahead of Umegaki while Sato dropped to fifth but was able to get up to third before the end of lap one. The slipstream available down the lengthy pit straight meant Suzuki never pulled away, and Sato made it a three-car group on lap five of 14.
Umegaki responded by going down Suzuki’s inside at turn one next time by, with Suzuki drawing back alongside approaching turn three but unable to pass. B-MAX Racing’s Tosei Moriyama joined the fight just before the safety car was summoned as debris was cleared from a two-car crash at turn 13.
Tokiya Suzuki
Racing resumed on lap nine and at turn one it was three-wide for the lead. Positions were held, while Syo Momose tried passing B-MAX team-mate Ayato Iwasaki for fifth at turn 13 but ended up losing two places.
There was no further battling up front before the safety car returned for the last two-and-a-half laps as B-MAX boss “Dragon”‘s stranded car was cleared from the turn one runoff. That secured victory for Suzuki, and meant Sato finished 11th as he had a five-second penalty for a start violation.
Shirasaki recovered to eighth, the place earned after it took several laps to pass Toyota junior Megumu Suzuki.
He had a chance at redemption in race two, having set a 1m45.935s to earn another pole by 0.116s over Sato. Tokiya Suzuki and Umegaki qualified third and fourth.
This time Shirasaki not only nailed the start but already had a big lead a few corners in, with Sato under pressure from several drivers behind. A turn one crash meant the safety car appeared on lap two, and Shirasaki ran away again once racing resumed on lap seven to win by 3.467s.
Moriyama was isolated in fourth, a position he took from Umegaki on the restart. Momose tried to go past on the inside too but they clashed, and he dropped to 20th.
Umegaki was instead passed by Honda junior Kotaro Shimbara and Ponos Racing’s Ryota Horachi, the 2024 Japanese F4 runner-up. The pair battled thereon, swapping places several times but that resulting in Umegaki getting back past them before the finish. However Horachi was classified fifth, as a five-second penalty demoted Umegaki to 10th.
Drivers’ race one fastest laps set race three’s grid, putting Sato on pole ahead of Shirasaki, Moriyama and Tokiya Suzuki.
Itsuki Sato
The poleman held the lead on the inside line into the opening corner, and Suzuki took third but Moriyama reclaimed it around the outside of turn three. It was three-wide for seventh heading to turn one the next lap, but the safety car was then called as five crashed cars needed clearing up.
Sato looked to the outside then the inside when racing resumed, and was alongside through turn one where two cars further back crashed. That led to another safety car interruption that ran to the end of a shortened 11-lap race.
The safety car accelerated away at turn 12 on lap 10, but Shirasaki came to a stop there with a drivetrain issue and seventh-placed Horachi also stopped with a fuel system. That meant the safety car had to remain out, and handed Sato victory.
Fuji also hosted round two on July 31-August 3, and this time Sato took a double pole. His fastest qualifying lap, a 1m46.341s, earned him race one pole by 0.158s over Shimbara, with Shirasaki trailing by 0.329s and Momose by 0.401s. Tokiya Suzuki was 10th fastest. Sato’s second-best laptime, a 1m46.375s, put him on race two pole by 0.224s. The top four was the same, and Suzuki was only 12th.
Race one had two formation laps due to a staller, then red flags waved half a lap in due to oil being laid down from the grid to turn two by Toyota junior Masana Muto. Sato had fended off an attack from Shimbara into turn one.
The race restarted behind the safety car 19 minutes later, and after two laps the field was released with four-and-a-half minutes left on the race clock. A turn one backmarker collision meant the safety car was summoned mid-lap, and the chequered flag waved a lap later. Sato earned half-points for victory, and a 40s penalty for overtaking behind the safety car dropped Suzuki from sixth to 38th.
The next day’s race ran green throughout. Shimbara went down Sato’s inside into the opening corner to take the lead, and on lap two Sato turned the outside there into the inside for turn three where he reclaimed first place.
Results round-up
Race
Circuit
Winner
Poleman
FL
1
Fuji Speedway
T Suzuki
R Shirasaki
I Sato
2
R Shirasaki
R Shirasaki
R Shirasaki
3
I Sato
R Shirasaki
4
Fuji Speedway
I Sato
I Sato
T Suzuki
5
I Sato
I Sato
I Sato
6
Suzuka
I Sato
K Shimbara
T Moriyama
7
K Shimbara
K Shimbara
I Sato
8
Sportsland Sugo
T Suzuki
T Suzuki
I Sato
9
T Suzuki
T Suzuki
I Sato
10
I Sato
I Sato
11
Autopolis
“Kentaro”
“Kentaro”
“Kentaro”
12
T Suzuki
T Suzuki
T Suzuki
13
N Imada
“Kentaro”
Y Sasaki
14
R Shirasaki
T Moriyama
R Shirasaki
15
Twin Ring Motegi
K Shimbara
K Shimbara
K Shimbara
16
R Shirasaki
I Sato
I Sato
The top three places were settled by the end of that lap, with Momose fourth. A charging Horachi, from seventh on the grid, was ahead by lap six. A lap three off sent Moriyama down to sixth, and Suzuki climbed up to seventh.
Round three at Suzuka followed on August 21-24, and Shimbara set the qualifying pace. A 2m08.212s earned him race one pole by 0.143s over points leader Sato, with OTG Motor Sports’ Kenta Kumagai 0.231s behind and Horachi a further 0.035s back in fourth. Suzuki qualified fifth, and a second covered the top 18.
Shimbara’s second-best laptime, marginally slower at 2m08.305s, delivered race two pole by 0.234s and this time Horachi was second. He edged Sato by 0.014s and Kumagai by 0.031s. Shirasaki qualified seventh and 12th, and a rules violation meant Moriyama had no laptimes count so started on the 15th row for both races.
Sato got alongside Shimbara into the first corner of race one, and stayed wheel-to-wheel until the poleman established himself ahead at turn three. Suzuki got up to third before the safety car was called due to a crash, and Shimbara weaved from turn 17 onwards ahead of the lap four restart.
It worked, as he was unchallenged while others fought behind. Horachi passed Kumagai for fourth into the chicane on lap six, then the safety car was needed again on lap eight.
Shimbara repeated his restart tactic for the final lap, but this time Sato was alongisde on the outside at turn one and that became the inside for turn three where he snatched the lead. Horachi tried going around Suzuki’s outside at turn 13 but went off and had to settle for fourth. Momose held off Shirasaki for sixth, Moriyama recovered to 16th and Drago Corse lost both of its drivers to crashes.
Shimbara, who was third in the 2024 standings, followed up three runner-up finishes with victory in race two. A crash meant the safety car interrupted lap one, and more drivers followed Shimbara in weaving before the lap three restart.
The field at Suzuka
Sato went straight past Horachi, who then had to hold off Momose into the final chicane. He slipstreamed past as lap four of 11 began, by which point Shimbara had a 1.5s lead and there was another 1.5s gap to third.
The safety car was needed again on lap six, and Shimbara was unchallenged on the lap nine restart. Racing was neutralised again a lap later due to two crashers at turn 15, locking in everyone’s positions to the end.
Akiland Racing’s Keito Matsui was hung out to dry on the outside at the chicane on lap four and fell from fifth to eighth, with Ponos’s Ryuma Sako then going around Kumagai’s outside when they reached turn one to take the position. But he went off at turn two and conceded three places, lifting Tokiya Suzuki to sixth.
Sato left Suzuka with a 39.5-point lead over Suzuki, with Shimbara the only other driver to have scored more than half of Sato’s 123.5-point tally.
Racing moved to Sportsland Sugo for round four on September 18-21, which was another triple-header.
Tokiya Suzuki claimed his first poles of the season, and by a comfortable margin. A 1m32.355s put him on top of the times in qualifying by 0.433s over team-mate Takahiro Kikuchi, then 0.042s split Sato, Kumagai and Megumu Suzuki in third to fifth place. Shirasaki was sixth, and Shimbara qualified 12th.
For race two, a 1m32.607s put Suzuki on pole by 0.279s. Kikuchi was second again, Sato trailed by 0.37s in third and Shirasaki pipped Kumagai to fourth by 0.006s. Shimbara’s final lap put him seventh.
A damp track, particularly on the inside of the grid, meant the safety car led a slick-shod field through the first two laps of race one. Suzuki instantly created a gap once racing got underway, as Kikuchi went off at turn one and rejoined in fifth then lost another spot.
Suzuki and Sato
Sato took second and was initially 1.2s behind, but by lap 11 he had cut the deficit to 0.434s and remained in Suzuki’s mirrors thereon. The lead fight ended on lap 14 of 17 as Ragno Motor Sport’s Kaoru Yoshida crashed out of 10th and triggered a safety car period than ran to the end.
Kumagai held third place throughout, with Megumu Suzuki initially fourth before Shirasaki took the position and pressured Kamagai for several laps. He was eventually shaken off, and TGM Grand Prix’s Leon Ochiai finished fifth ahead of Umegaki, Suzuki and Matsui, who was warned for clashing with Momose when defending. Kikuchi was 10th.
Puddles remained for race two, but slick tyres were used again and the safety car featured for the first two laps.
Suzuki’s early pace advantage was even more pronounced this time, although part of the reason he had a 3.7s lead by lap seven was down to Sato trying to go down Kikuchi’s inside at turn one on lap six and contact being made which sent Kikuchi spinning and meant he finished 34th.
Sato then chased down Suzuki, and was 1.488s behind when the leader rode some kerbs and almost spun on lap 15. That brought the gap down to 0.585s, and Sato was all over him on the final lap.
Shirasaki was a lonely third, then Sako, Kumagai, Shimbara and Matsui were fighting behind. Kumagai went off at the final corner on lap 11, which consigned him to ninth, and Matsui went around the outside of Shimbara through turn three on the last lap but a five-second penalty for dangerous driving dropped him from fifth to 14th.
Race one’s fastest laps set race three’s grid, and Sato beat Tokiya Suzuki to pole by just 0.046s. The safety car was utilised in the same way as the previous day, and Sato romped to victory.
A field of over 40 cars at Fuji
He was 2.1s clear when the safety car was called on lap 11 after Horachi’s overtaking attempt on OTG’s Miki Onaga for ninth at Horseback Corner led to them colliding and spinning. Four laps remained when green flags waved again, and Sato pulled away by 1.583s. Shirasaki and Umegaki were third and fourth, while Shimbara’s title homes were significantly diminished in 16th after also non-scoring in race one by finishing 13th.
Sato had a 32.5-point lead over Suzuki with two rounds to go, with Shirasaki 84 points back and Shimbara needing to win every remaining race and requiring Sato to score no more than three points and Suzuki no more than 36.
Their hopes ended in race two at Autopolis on October 18, as Sato collected his 10th successive top-two finish while Suzuki earned his fourth victory of 2025 (but only his fifth finish in the top two).
The title contenders didn’t contest race one on Saturday, as Japanese F4’s ‘champion’ and ‘independent’ classes were split for the weekend in qualifying and the races. Races one and three were contested by the latter, while the usual frontrunners were in races two and four.
Field Motorsports’ “Kentaro” set a 1m55.650s to take race one pole by 0.413s, with 0.085s splitting Nobuhiro Imada (B-MAX), Yasuhiro Shimizu (B-MAX) and Masayuki Ueda (Rn-sports) in second, third and fourth. “Kentaro” converted pole into victory with ease on Saturday, and Imada was way ahead of Ueda. “Dragon” was fourth, and there was one retiree in the 16-car field.
Second-best laptimes from Friday’s qualifying established race three’s grid for Sunday morning, putting “Kentaro” on pole again but by a tiny margin. His 1m56.080s earned him first place by 0.065s over Imada, with Shimizu 0.09s off pole.
It was incredibly foggy, and the safety car led the first six laps. After green flags waved, Imada went to “Kentaro”‘s outside of turn three, which became the inside for turn four where he took the lead. Shimizu and Ueda got past later in the lap, then the safety car returned on lap eight as “Dragon” and Rn-sports’ Isao Nakashima crashed out while disputing fourth.
The race ended after 10 of the scheduled 13 laps, with Imada victorious. In one weekend, “Dragon” had gone from being the class’s points leader to sitting behind “Kentaro” and Imada in the standings.
In the ‘championship’ class, most set personal bests after three or four laps in qualifying, with only one driver improving late on. Tokiya Suzuki was quickest, by a tiny 0.01s, after setting a 1m53.535s and Moriyama made a return to form by being second fastest. Sato was third, 0.233s back and 0.022s ahead of Muto and Shirasaki. Momose was 0.276s off pole in sixth.
Moriyama fared even better on second-best laptimes, taking race four pole with a 1m53.685s. Top spot was earned by 0.111s, with Shirasaki beating Sato to second by 0.005s. Momose and Muto were next up, and Suzuki qualified seventh.
Suzuki led race two lights-to-flag, while Moriyama had lost out to Sato, Muto by the opening corner then was wheel-to-wheel with Shirasaki until turn four where he nosed back ahead.
Shimbara started eighth and was past Shirasaki for fifth before the safety car appeared due to fluid on track. The field was released again on lap four, and Shirasaki took fourth in a three-wide move at turn one. He then stuck with Muto, while the top two streaked away. Suzuki was victorious by 6.675s over Sato, with Muto a further 1.95s behind.
On lap nine of 13 Momose passed Shimbara, who then slid off at the last corner and was overtaken by Horachi too.
Moriyama was outdone at the start again the next day, this time conceding the lead to Shirasaki immediately then running side-by-side with Sato until turn four where he braked later. Sato was forced to go wide, dropping to seventh then reclaiming a spot by passing Muto. Horachi was also sent wide during a multi-car squabble mid-lap, and Sato slipped through for fifth.
With no interruptions, Shirasaki was able to build a 5.969s lead over Moriyama, who had Momose, Suzuki, Sato and Horachi in a train behind him the rest of the race but without anyone attacking each other.
Ryo Shirasaki
Sato’s first podium-free race since the season opener led to his championship lead being reduced to 23.5 points ahead of the finale at Twin Ring Motegi on October 30-November 2.
Shimbara and Shirasaki outpaced the title contenders in qualifying, with 0.067s splitting the pair. Suzuki was 0.119s off Shimbara’s 2m00.232s pole time in third, and just 0.002s faster than Sato. Moriyama languished down in 18th, behind four ‘independent’ drivers including Ken Alex who was fifth fastest overall.
However the two classes had run separately, with the independents getting a grippier track, and Alex would lead their contingent from 30th on the grid.
It was a different story at the front when it came to second-best laptimes, and a late 2m00.637s earned Sato pole for the title decider by an all-important 0.055s over rival Suzuki. Alex was third fastest and 0.111s shy of overall pole, but would start 30th again and instead Shirasaki and Umegaki filled row two of the grid.
There was drama before race one began, as at the end of the formation lap Sato signalled he was unable to start his car and so a second formation lap was added while his car was wheeled into the pitlane.
Suzuki was hungry to capitalise from that stroke of luck to the maximum and he attacked Shirasaki into turns two and four on the opening lap. He got his move done, and Toyota junior Yuzuki Miura followed him through.
Later in the lap Horachi overtook Shirasaki too, while Sato joined the action but then stopped at the side of the track. Another driver spun, and the safety car was summoned on lap two to clear the two cars. Horachi had taken third before racing was neutralised, and the gap that had already opened up to the top two was eradicated.
Racing resumed on lap five of 12, and Umegaki was next to clear Shirasaki. He then lost out in a fight with Sako, while Umegaki escaped up the road and passed Miura mid-race.
Shimbara claimed his second win of 2025 by 3.924s, with Suzuki closing to within 5.5 points of Sato by finishing second.
“Kentaro” had entered the weekend 0.5 points ahead of Imada, with “Dragon” 15 points from the top. By finishing 29th, Imada moved to top of the ‘independent’ class standings by 9.5 points.
With the overall title contenders sharing the front row for the finale, the stakes were at their highest.
Suzuki made the better start and took the lead on the inside turn one but locked up. That allowed Sato to do a switchback and be on the inside for the second part of the twin-apex corner where he got ahead. Their rear wheels rubbed and Suzuki was sent over the outside kerbs, but he maintained speed and went down Sato’s inside at turn three. That led to banging wheels again at the exit, and Sato was sent far into the dirt of the runoff and after rejoining was down in 25th.
It looked like the title was now over for Sato, but both drivers got five-second penalties for contact and Shirasaki went around the outside of Suzuki at turn four for the lead.
The safety car was on track from laps two to four, and in the racing that followed Sato charged up to 13th before his penalty knocked him back down a spot. His title ambitions rested in how potent Suzuki’s penalty would prove, but it only dropped him from second to fourth so the Toyota junior clinched the crown by 6.5 points.
Shirasaki won, Umegaki bookended his season with second place finishes, and Miura made the podium after fending off Horachi. Kentaro finished 26th, and Imada beat him to the title by half a point by finishing 2.247s behind him in 27th.
2025 championship standings
Pos.
Driver
Team
W
P
FL
Podiums
Points
1
T Suzuki
TGR-DC RS
4
3
2
9
219
2
I Sato
Kageyama Racing
5
3
7
10
212.5
3
R Shirasaki
Kageyama Racing
3
2
3
7
168.5
4
K Shimbara
HFDP w/ B-MAX
2
3
1
5
127
5
R Horachi
Ponos Racing
1
98
6
S Momose
HFDP w/ B-MAX
2
96
7
K Umegaki
TGR-DC RS
2
89
8
T Moriyama
B-MAX Racing
1
1
3
87
9
K Kumagai
OTG Motor Sports
1
50.5
10
R Sako
Ponos Racing
37
In early October, Honda Racing School held its final scholarship selection test of the year at Suzuka and its principal Takuma Sato, a former IndyCar and Formula 1 driver, picked Kota Tsuchihashi to be a Honda junior in single-seaters next year.
The 18-year-old graduated from karts, where he represented Japan at the Motorsport Games, into his home country’s entry-level Super FJ category this year and will likely spend 2026 racing in either French F4 or Japanese F4.
AloJapan.com