The protagonist travels to another world and becomes a pig, an ugly wild boar. Since he is a pig, how can he become a human? The protagonist doesn't know either. He only knows that if he wants to live, he must rely on the system and conquer all realms. There is no guarantee that one day the system master will be merciful and he will return his body to others.
This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.