In 2000, a mysterious ruin was being excavated at Kuroyama in the mountains of Nagano. A coffin inside the ruins contained an ancient corpse wearing a petrified belt. Little did the team know that when they opened the coffin, they also awakened their mortal enemy, the Gurongi. The team was immediately attacked by an unidentified life form and all of them died. In order to find clues to the murder of the team, a young man suddenly broke into the scene of the ruins of Nagano Prefecture Detective Kaoru Ichijo, who was investigating the ruins. The young man who was stopped by Ichijo called himself the adventurer Yusuke Godai. The unidentified life form that finally resurrected appeared in the suburbs of Nagano and began to attack people at will, even rushing into the police station. Yusuke, who was present, sensed the image of a warrior from the belt-shaped relic unearthed from the ruins and kept by the police, and wore it around his waist according to the adventurer's intuition. Yusuke's body was also covered with a layer of armor. After the transformation, Yusuke fought a hard battle with the unidentified life form that attacked the police station and finally defeated it. As unidentified life forms continue to appear in the big city of Tokyo, Yusuke Godai is determined to fight to free the people around him from fear and protect their smiles... A new generation of Kamen Rider "Kuuga" is born!