Xia Xing, a boy in the throes of his chuunibyou phase, doesn't find the gaming friend he arranged to meet in-game that day. On his way home, he unexpectedly obtains the Regret Fulfillment System. After gathering evidence and going through a series of tests, he chooses to believe this absurd reality. Then, little by little, he uses his own methods and the System to try to change the course of his life. But will things really go smoothly along the way?
