I'm Standing on a Million Lives

The boy Yotsuya saved in the Chinese restaurant, Torii Keita, turns out to be the fifth player. They're sent to the alternate world again, and after receiving the fifth quest, they head for Cortonel to track down some leads. There they find Kahvel, who is now a mother. The party is shocked to learn that 15 years have passed since their fourth quest, but that isn't the only thing that's changed in this world.