Autumn is here. One day after Akina 86 was modified with a turbocharged engine and defeated Akiyama Wataru, Takahashi Ryosuke suddenly visited and invited Takumi to join, hoping to gather the masters of Gunma Prefecture to challenge the mountain roads across the country. Takumi hesitated and did not immediately accept Takahashi Ryosuke's invitation. He felt that he had some other things to deal with. First, Takumi went to Nikko to challenge Sudo Kyoichi of the Emperor Team and had a fierce race. On the winding Iharo Mountain Road, Takumi, who was ahead, did not let Sudo Kyoichi overtake him. It seemed that Takumi won, but Takumi thought that he was just tied with Sudo Kyoichi, and this made him feel very satisfied. A few days later, Kobayashi, also a driver from Nikko, came to Akina to challenge Takumi. Kobayashi's original opponent was Sudo Kyoichi, but he was defeated by Takumi first, so Kobayashi naturally shifted his target to Takumi. At the same time, Kashiwa's father and Takumi's father turned out to be old rivals! A feud between two generations unfolded on the Iboro Mountain Road... Kashiwa used the corner of the mountain road to jump (that is, from the upper mountain road, instead of taking the correct lane, he directly used the height difference to jump over the corner to the next mountain road) and surpassed Takumi in the middle section, but Takumi quickly mastered this crazy driving method, and in the last section of the road he caught up with Kashiwa by driving in the ditch. Before the finish line, Kashiwa's car slipped because of the fallen leaves on the road, and Takumi won the race by a hair's breadth... When Takumi was confused about the direction after graduation, his attitude towards Mogi Natsuki also began to change. Takumi, who had alienated Mogi after learning that Mogi Natsuki had an compensated dating relationship with Kaiheiji's man, finally reconciled with Mogi thanks to Mogi's efforts. However, Takumi's senior from the same school, Yuki from the football team (the one who called Takumi in junior high school) returned to Akina during the Christmas holiday and forcibly took Mogi Natsuki away in order to renew their relationship. After receiving Mogi's call for help, Takumi drove the 86 and fought with Yuki's LANEVO3 in the snowy Akina Mountain, and finally rescued Mogi Natsuki. On the way back, Mogi Natsuki finally told Takumi what he was thinking... Finally, spring came, high school graduated, Takeuchi Shu became a formal employee of GS gas station, Mogi Natsuki went to Tokyo to study, and Takumi told Mogi Natsuki at the Akina Lake that he wanted to become a professional driver and his ideal of becoming the fastest and strongest racing driver... Project D plan... is gradually being carried out...