Tatsuya Kimura, feeling overshadowed by his champion friends Ippo Makunouchi and Mamoru Takamura, yearns to claim the title of Japan's Junior Lightweight boxing champion. To achieve this, he partners with Ippo's rival, Ichirou Miyata, who seeks redemption after a defeat by the current champion, Ryo Mashiba. As Kimura gears up for a showdown with Mashiba, the reigning champ fights not only to retain his belt but also to secure a brighter future for his sister Kumi. In a battle between Kimura's fierce determination and Mashiba's steadfast resolve, who will emerge victorious in the ring?