Digimon Mystery Dungeon, a Pokemon Mystery Dungeon-esque AU set in the Digimon universe.

A Digimon RPG is released worldwide that allows you to play as Digimon only, with no human interference. However, after the release, more and more players have begun to disappear. While the reason is unknown to most, the true cause is that Yggdrasil has been picking out humans playing the game to come to the Digital World to help save it.