Toyota juniors Rikuto Kobayashi and Jin Nakamura won the opening two races of the Japanese Formula 4 season at Fuji Speedway.
The weekend started with two sets of practice sessions. Honda junior Yusuke Mitsui was fastest across the first group of three sessions, setting a 1m46.278s to lead fellow Honda junior Tosei Moriyama by 0.077 seconds and Kobayashi by 0.093s, with the top 22 within a second.
Honda junior Yuto Nomura was 0.158s back in fourth, and fastest in the next group of three sessions. He set a 1m45.937s, putting him 0.036s up on Moriyama, 0.082s ahead of Mitsui and 0.136s up on Kobayashi.
The 46-car field was split into two groups for qualifying, with the driver who topped the faster group earning pole. Kobayashi achieved the feat in Group A, heading Itsuki Sato by 0.232s and bettering Group B pacesetter Mitsui by 0.130s.
They shared the race one front row, with Sato and Nakamura on row two, then each of the remaining rows filled by one driver from each group going down in pace order.
Kobayashi started strongly from pole, while Mitsui floundered and Nakamura tried overtaking him into turn one but they collided. Mitsui was spun around and Rin Arakawa and Kazuhisa Urabe had to take late avoiding action.
Later in the lap, Ryoma Henzan, Hironobu Shimizu and Kohei Tokumasu retired in a clash, which Shion Tsujimoto then got caught up in and led to her retiring too.
Sato moved into second place, and Nomura battled Toyota junior Shunji Okumoto for third until the safety car was summoned.
Racing resumed on lap four of 14 and Nomura went for Sato around the outside of turn one. His rear-right wheel hit Sato’s front-left and pitched him airborne, spinning, and then into retirement.
Kobayashi led by a big margin, Sato retained second, and Okumoto, Moriyama and Kento Omiya fought hard over third and fourth.
Omiya made a diving move for third at turn 10 on lap seven, and his defences thereon brought Toyota junior Yuki Sano into the fight. Moriyama passed Okumoto for fourth into turn one on lap 10, then everyone in the group gained a place as Sato served a drive-through penalty for being involved in a collision.
On lap 12 Moriyama passed a weaving Omiya for second into turn one, and on the final lap Omiya tried to prevent Okumoto making the same move. Instead he locked up, forcing Okumoto off and allowing Sano to pass both.
He dived back past Sano at turn 10, with Okumoto also moving back ahead of his team-mate. Kobayashi won by 8.169s over Moriyama, who got penalised 10s for overtaking off-track, so Okumoto took second after passing Omiya in a photo finish by 0.033s.
A 10s penalty for pushing Okumoto off meant Omiya actually finished 15th, while Arakawa recovered to 11th before a 40s penalty for a false start left him 34th. Nakamura was penalised 40s for his lap one collision, but retired.
The second-best qualifying laptimes set race two’s grid, with Kobayashi and Mitsui on front row duty again. Mitsui spun on the formation lap, but then overtook a group of cars to reclaim his grid slot for the start.
Again there was a lap one summoning of the safety car, as Tomohito Watabe and Tsujimoto collided at turn 10. Yutaka Toriba then hit Tsujimoto and had to retire in the pits, before Hachiro Osaka also hit Tsujimoto.
Fuma Horio crashed into Watabe’s spun car, then Tadakazu Kojima drove into the stationary Horio. Omiya was another lap one retiree, and racing resumed at the start of lap six.
Mitsui was all over Kobayashi straight away and passed him at turn one as Kobayashi went off and dropped to fourth behind Nomura and Nakamura, who passed Nomura for second on lap eight.
The trio fought to the end for what was second, with Kobayashi briefly passing Nomura into turn one on the last lap. Leader Mitsui had a 40s penalty for a false start at the restart, meaning Nakamura won ahead of Nomura and Kobayashi. Mitsui was classified 28th.
Moriyama won a lengthy battle with Sato and Okumoto for fifth, and outside of the points Yuta Fujiwara was shown the black-and-white flag for repeated track limits abuse. At the very back, several drivers were penalised 40s for collisions and going off track during the safety car period.
Race 1 (14 laps)
1 Rikuto Kobayashi TGR-DC RS 27m22.217s
2 Shunji Okumoto TGR-DC RS +11.813s
3 Yuki Sano TGR-DC RS +12.230s
4 Kazuma Nishimura Media Do Kageyama Racing +12.811s
5 Yuki Mishima Bionic Jack Racing +13.377s
6 Ryota Horachi Akiland Racing +16.059s
7 Rio Shimono Zap Speed +16.219s
8 Hibiki Komatsu Skill Speed +17.491s
9 Tosei Moriyama HFDP +18.169s
10 Yuta Fujiwara Akiland Racing +18.760s
Pole: Kobayashi, 1m45.396s
Fastest lap: Rin Arakawa, 1m45.620s
Race 2 (14 laps)
1 Jin Nakamura TGR-DC RS 30m10.169s
2 Yuto Nomura HFDP +0.567s
3 Kobayashi +1.171s
4 Rin Arakawa Zap Speed +3.090s
5 Moriyama +6.274s
6 Itsuki Sato Helm Motorsports +6.323s
7 Okumoto +7.777s
8 Kazuhisa Urabe Bionic Jack Racing +9.746s
9 Sano +10.667s
10 Mishima +11.653s
P: Kobayashi, 1m45.499s
FL: Mitsui, 1m45.368s
1 Kobayashi 40 2 Nakamura 25 3 Okumoto 24 4 Nomura 18 5 Sano 17 6 Nishimura 12 7 Arakawa 12 8 Moriyama 12 9 Mishima 11 10 Horachi 8