A sequel to one of the endings of Taimanin Asagi 3. Set in an alternate-universe "reset world", Taimanin Asagi ZERO is set prior to the events of the main series. All of the game's characters are younger than in the main series, and a number of other key alternate-universe differences are also apparent. A young Asagi, not yet aligned with any government organization, is recruited by the Minister of Public Safety to counter a dangerous threat. In the merciless world of Taimanin Asagi ZERO, only a single mistake could cause a cruel death. Will you be able to defend Asagi from various tragic fates and lead her to achieve missions!?