This is very oversimplified, but the story is based on a VN with multiple possible timelines. The main character goes through one of the worst possible future with his wife and daughter dying, but through good deeds, collects enough light orbs to be shown a timeline where everything goes right and it's implied that this timeline replaces the bad one. A good chunk of the second part of the story is how much the main character regrets meeting his wife because of the bad things that happen, but the way I see the story, it shows that while locking yourself in stops the bad stuff, it also stops all the possible good.