Five people went camping together, and inexplicably met an old man in a cave whose only eyes were not white, saying that they had reached the end of their lifespan. Old man, you're not joking like this, are you going to reincarnate us? Are you going to use us as ghost-hunting coolies? Then we can just force it out and blackmail you for a while before leaving. Anyway, they are all orphans, and only each other is left in this world. When they get together in another time and space, there is already someone around them who wants to watch over them for the rest of their lives...