People and nail people share the same continent and are in constant struggle against each other. At some point a relative peace has been settled and both populations continued to coexist in several smaller nations.
The stage is Altair Kingdom. Jam Rock is a famous swordsman. One day on the way home from the swordsmen dojo, he helped a girl chased by suspicious men. She only remembered her name - Minwi. She turned out to be a shrine maid of Zainhad Temple and her memory was sealed for some reason. Jam Rock decided to take her to the Temple of Zainhad, but he was declared as Minwi kidnapper.
Two people passed through the security net and reached the Temple of Zainhad. However, Minwi could not remember anything. That night Minwi was kidnapped by the nail people with a probable aim to bring her as sacrifice to gods. Jam Rock's rescue adventure is only beginning now.