Keyaru, who is exploited repeatedly by others due to being a healing magician, notices what lays beyond just his healing magic, and is convinced that a healing magician is the strongest class in the world. However, by the time he realizes his own potential, he is already deprived of everything. Thus, he uses healing magic on the world itself to go back four years into the past, deciding to redo everything and get revenge on the ones who exploited him.