The protagonist of the story, Duowen Sanzhiro, is a passionate and energetic young man, but he is very reckless and sloppy, and often does things without thinking. He lived on an outlying island since he was a child, until he was noticed by the monster "Bubai" from the world of "Yonimen", and thus embarked on the road of fighting. In the "Monster City", he saw monsters being sealed and turned into "strike symbols", and decided to help these monsters and protect the Monster City from threats. However, the person he fears most is his mother and childhood sweetheart Xiao Wei. Although he is good at using the fire attribute, other attributes can also be used flexibly
During the journey, Sanzhiro Duowen will encounter various monsters and enemies, and have fierce battles with them fighting. He will also make many new friends, and by fighting with them, he will gradually grow into a true monster fighter. In the end, he will return to the outlying island to show his mother and Xiao Wei how he grew up and everything he has experienced.