Kjófu no route 87 (E20)

A boy showed up to the headquarters of SSSP one day after a mysterious phenomenon occurred at Omuroyama in Izu. He warned Fuji that Highland Dragon Hydra of Mt. Omuro Park would rage While SSSP investigates the vicinity of Mt. Omuro, the identity of the boy was revealed, and surprisingly he was the person who died in a traffic accident six months ago. And as the boy's warning, Hydra appeared! (Prime Video)