Kai is an average sixteen-year-old student of Goldenville High School. One day he finds a strange object in the locker room and after he interacts with it, he starts seeing abnormal creatures he couldnt see before. It doesn’t take long before Kai realizes he also gained special powers, which allow him to face those bizarre beings. However, those beasts do not like to be found, and soon an experienced one is sent to Kai’s home to finish him off. Not finding him there, it ends up killing his parents by mistake. Kai abandons his school life and vows to avenge his parents’ death. Kai is forced into this mystery world in the border of reality, hunting monsters that plague the world and strengthening himself with the aid of people like him.

Josiah lives a pathetic life at a retail job in the suburbs of a dangerous town. One day, he is attacked and murdered on the street.

After his death, Josiah realizes he now lives in the body of a baby from another world. He is now the first son of the emperor and heir to the throne. His bewildered birth happens during a storming of the castle - and his mother, who has fallen victim of a plot, is forced to leave the castle with him and run to a neighboring town.

With the mind of an adult from another world, Josiah quickly masters the world’s art of ‘binding weapons’, becoming a powerful combatant. He rises through the ranks in the kingdom of Bucoa, focusing on his goal of avenging his mother and claiming his birthright - the throne.
----------
“Ok, little one. Let’s do it like this. Show me what you got. Just you and me. If you can win against me, I’m going to let your friends go.”

Josiah braced his sword and stood up to it. He couldn’t have asked for a better deal himself.

“Come, then. I’ll show you hell.”