The One Who Should Not Exist

[Synopsis] A mysterious entity that connects countless worlds—people call it the “Unknown System.” Those connected to the System live by completing quests and using U-Coins, which are necessary to obtain weapons, abilities, and various other items. However, the moment their U-Coins reach zero, their very existence vanishes. Zairef, an ordinary human from Earth who had nothing to do with the System, is suddenly abducted by an unknown entity and taken to the Unknown System one day. Yet he had no memory of why he had been brought here. Upon waking in a mysterious place, he meets a girl named Azedenya and learns that he is being treated as a System user—and that he must complete quests. Five years have passed since then—Zairef continues to complete quests within the Unknown System, surviving while battling enemies and experiencing various events. However, his questions extend beyond mere survival. Why is human existence itself bound by a system called U-Coins? Who created this unknown system? Why does the system erase the existence of those who lose their U-Coins? And why was he brought here in the first place? Through encounters with new people, battles against countless enemies, and the pursuit of the mysteries hidden within the unknown system, Zairef searches for the truth. And in the end, only one question remains: Can he return to Earth?