If the Brave Man Lies Flat, Who Will Save the World?

Four years after the Demon King defeated the previous hero, the wall of the human kingdom was shattered by a single blow from the Demon King's general. A group of newly summoned braves shouted "defend the kingdom", but disappeared collectively when the city was destroyed. In despair, the princess remembered the man who lost to the devil four years ago. "Father, maybe only he can save this world." At this moment, the former brave man was fishing by the river, thinking about what to add to his family's pets at night...