Shin Megami Tensei IV: Apocalypse takes place in the 2030s, within the same setting as Shin Megami Tensei IV. Twenty-five years prior, a devastating war was waged between the angels and the armies of Lucifer. To protect Tokyo from damage, a great rock dome was created. While it protected Tokyo, resources became progressively scarcer over the following years, while angels and demons ruled over the human population.
Source: Wikipedia, "[en.wikipedia.org/wiki/Shin_Megami_Tensei_IV%3A_Apocalypse Shin Megami Tensei IV: Apocalypse]", available under the CC-BY-SA License.
