Two years after the events of Kengan Ashura, a young man named Narushima Kouga aims to enter the Kengan matches, seeking Tokita Ouma for a yet unknown reason. He begins to work under Yamashita Kazuo when he meets Gaou Ryuuki, a splitting image of Ouma. As a massive showdown between the Kengan Association and Purgatory, another underground martial-arts fighting organization looms in the background, how will Kouga become strong enough to enter in the legendary Kengan fights?