The 2026 Japanese F4 Championship continued at Okayama International Circuit, where Ryo Shirasaki produced a perfect response to his scoreless opening round at Fuji Speedway.
The Hydrangea Kageyama Racing driver claimed both pole positions and converted them into two victories. As a result, he climbed to second in the Champion Class standings with 50 points.
Masana Muto, meanwhile, finished second in both races and moved into the championship lead on 69 points. Previous leader Buntaro Igarashi failed to score after qualifying 19th, leaving him tied with Kenta Kumagai on 40 points.
Results from Round 2 of the 2026 Japanese F4 season at Okayama
Shirasaki delivers a perfect Okayama weekend
Shirasaki set the pace in Qualifying and secured pole for Race 1 by only 0.051 seconds over Toyota junior Muto. Mitsusada Racing’s Ryutaro Sakai followed in third, just 0.166 seconds behind the benchmark.
The drivers’ second-fastest laps determined the grid for Race 2. Shirasaki again led Muto and Ryutaro Sakai, giving the same three drivers the leading positions for both contests.
However, Igarashi endured a difficult session and qualified only 19th. Honda junior Syo Momose also struggled and placed 24th, leaving both drivers with significant ground to recover around a circuit with limited overtaking opportunities.
In Race 1, Shirasaki maintained the lead at the start, while Muto held second. Ryutaro Sakai dropped from third to fifth behind Ryo Sakai and Yuzuki Miura but quickly recovered fourth around the outside of Turn 4.
Officials deployed the Safety Car after Tomoki Terashima crashed during the opening lap. Racing resumed at the end of lap four, but the interruption did not prevent Shirasaki and Muto from pulling clear.
The positions remained unchanged at the front, and Shirasaki secured his first victory of the season. Muto finished second, while Ryo Sakai resisted Ryutaro Sakai to claim his maiden Japanese F4 podium.
Shirasaki completes the double
Race 2 produced a similar start, with Shirasaki leading Muto into the opening corner.
Ryutaro Sakai again lost positions and dropped behind Lu You De and Ryo Sakai. However, he recovered fourth around the outside of Turn 4, passing Ryo Sakai before the end of the opening lap.
A collision involving Masaki Murata and Soichiro Shioda brought out the Safety Car on lap three. The race resumed at the end of lap seven, with Shirasaki controlling the restart ahead of Muto and Lu.
While Shirasaki and Muto maintained a steady gap at the front, Ryutaro Sakai began closing on Lu in the fight for third. By lap 12, less than half a second separated them.
Sakai finally launched an attack on the last lap. After an unsuccessful attempt around the outside of Turn 5, he positioned himself alongside Lu through Turns 6 and 7 before completing the pass at Turn 8.
The move earned Sakai third place and made him the youngest podium finisher in Japanese F4 history at 15 years old.
Shirasaki took his second victory of the weekend ahead of Muto. The result marked his fifth career Japanese F4 win and completed a perfect recovery from his scoreless Fuji opener.
Champion Class standings reshaped
Muto leads the Champion Class standings with 69 points after adding two second-place finishes to his victory and sixth place at Fuji.
Shirasaki’s double victory moved him from zero points to second on 50. He now sits 19 points behind Muto after winning both races at Okayama.
Igarashi fell from first to third after finishing 16th and 12th. Consequently, he remained on 40 points and failed to score for the first time this season.
Kumagai also holds 40 points after finishing eighth and seventh. Yuzuki Miura follows in fifth with 34 points, while Ryutaro Sakai and Ryo Sakai share sixth and seventh on 27.
Haruto Nakai and Lu hold 18 points each, while Momose completes the top 10 with 16.
In the teams’ standings, TGR-DC Racing School leads with 86 points. Hydrangea Kageyama Racing climbed to second on 58 after Shirasaki’s double victory, while OTG Motor Sports sits third with 30.
Mitsusada Racing follows on 27 points. B-Max Engineering, HFDP with B-Max Racing Team and Akiland Racing each hold 18. Only each team’s highest-finishing driver scores towards the Teams’ Championship.
2026 Japanese F4 Standings after Round 2 at Okayama: Champion Class
Drivers’ Standings
- M. Muto – 69 points
- R. Shirasaki – 50 points
- B. Igarashi – 40 points
- K. Kumagai – 40 points
- Y. Miura – 34 points
- R. Sakai – 27 points
- R. Sakai – 27 points
- H. Nakai – 18 points
- Y. D. Lu – 18 points
- S. Momose – 16 points
- Y. Suzuki – 14 points
- S. Yamamoto – 10 points
- L. Ochiai – 10 points
- M. Hamabe – 10 points
- T. Terashima – 6 points
- M. Onaga – 6 points
- R. Nakazato – 5 points
- K. Kurosawa – 3 points
- M. Murata – 1 point
Teams’ Standings
- TGR-DC Racing School – 86 points
- HYDRANGEA Kageyama Racing – 58 points
- OTG MOTOR SPORTS – 30 points
- Mitsusada Racing – 27 points
- B-MAX ENGINEERING – 18 points
- HFDP with B-Max Racing Team – 18 points
- AKILAND Racing – 18 points
- FALCON Motorsport – 10 points
- Team 5ZIGEN – 10 points
- ZAP SPEED – 1 point
Hirobon controls the Independent Class
While Shirasaki dominated the Champion Class, “Hirobon” delivered his own sweep in the Independent Class.
The 2021 class champion secured pole for both races and converted each starting position into victory. As a result, he moved from sixth in the standings to the championship lead.
In Race 1, Masayuki Ueda made the stronger start and briefly took the lead. However, Hirobon regained first later in the opening lap and began building an advantage.
Ueda later received a 10-second penalty for a jump start before retiring in the pits. “Kentaro” consequently moved into second, while “Ikari” completed the podium.
Previous championship leader Yutaka Toriba recovered from a grid penalty to finish fourth, but the result ended his winning run after he swept the opening round at Fuji.
Hirobon again controlled Race 2 from pole. Behind him, Ueda moved into second, while Toriba became stranded in the gravel at Turn 1 and triggered a Safety Car.
Once racing resumed, Kentaro closed on Ueda and reclaimed second at the hairpin on lap 11. Hirobon remained clear at the front and completed his second victory of the weekend.
Kentaro finished second for the second time, while Ueda secured third.
Independent Class battle tightens
Hirobon leads the Independent Class standings with 65 points after his Okayama sweep.
Toriba sits only three points behind on 62. Although he finished fourth in Race 1 and retired from Race 2, his double victory at Fuji kept him firmly in championship contention.
Ikari holds third with 47 points after adding third and sixth-place finishes. Masayoshi Oyama follows on 43, while Kentaro’s two second places moved him to fifth with 36.
Nobuhiro Imada remains sixth with 26 points despite missing Okayama. “Dragon” follows on 24, two points ahead of Isao Nakashima.
In the Independent Class teams’ standings, Team 5ZIGEN leads with 65 points after Hirobon’s double victory. Hydrangea Kageyama Racing sits second on 62, while Bionic Jack Racing holds third with 47.
Akiland Racing follows on 43 points, only one ahead of B-Max Engineering. Field Motorsport and Rn-sports remain close behind with 36 and 35 respectively.
2026 Japanese F4 Standings after Round 2 at Okayama: Independent Class
Drivers’ Standings
- Hirobon – 65 points
- Y. Toriba – 62 points
- Ikari – 47 points
- M. Oyama – 43 points
- Kentaro – 36 points
- N. Imada – 26 points
- Dragon – 24 points
- I. Nakashima – 22 points
- William – 16 points
- M. Ueda – 15 points
- S. Akamatsu – 14 points
- G. Shimizu – 14 points
- M. Saito – 9 points
- H. Sugiyama – 6 points
- K. Kojima – 4 points
- S. Nagashima – 1 point
Teams’ Standings
- Team 5ZIGEN – 65 points
- HYDRANGEA Kageyama Racing – 62 points
- Bionic Jack Racing – 47 points
- AKILAND Racing – 43 points
- B-MAX ENGINEERING – 42 points
- Field Motorsport – 36 points
- Rn-sports – 35 points
- HELM MOTORSPORTS – 16 points
- ZAP SPEED – 14 points
- Eagle Sport – 14 points
- Buzz Racing – 1 point
Okayama creates new championship leaders
Round 2 transformed both Japanese F4 title battles. Shirasaki delivered a perfect Champion Class weekend after failing to score at Fuji. His two victories immediately established him as Muto’s nearest championship rival.
However, Muto’s consistency gave him the standings lead. He has now won once and finished second twice across the opening four races, while Igarashi must recover after leaving Okayama without points.
Hirobon produced a similarly decisive response in the Independent Class. His double victory overturned Toriba’s early advantage and left the former champions separated by only three points.
As Japanese F4 prepares to return to Fuji Speedway, Muto carries the Champion Class lead, while Hirobon heads an increasingly close Independent Class contest.
