The boy at number 7 will rise from the bottom!

In a certain place, there was a boy who spent his days being called "Number 7" by those around him. The boy was forced to work under thieves, and because his emotions and senses were half-numbed, he didn't notice the abnormality of his daily life. However, one day, the thieves are attacked by monsters and completely wiped out. The boy is spared by the monster and decides to go down to town. What will the former slave boy, who has virtually no general knowledge, do from now on? The success story of the boy called "Number 7"!! I've changed the title of the novel slightly.