The story unfolds against the backdrop of ancient fossils sleeping in Fusama Magna gathering together and transforming into a giant monster that heads to Tokyo. Humans regard it as a natural disaster, but only the monsters notice the truth and begin to worry about the future. If this continues, the world will end. The one who can block this phenomenon is Watanabe, an elementary school student in Tokorozawa, Saitama Prefecture, who has inherited the bloodline of the legendary monster hunter. The boy who is regarded as a brave man who can save the world and the monsters involved embark on a great adventure.