It looks like quite a bit of information leaked regarding Shin Megami Tensei V, including its story details and release date, from a premature update on its official Japanese website. Persona Central caught all of the information, which has since been taken down.
The main character of Shin Megami Tensei V is an ordinary high school student who wanders into another world called “Da’ath.” The student then fuses with a mysterious man and becomes a “Naobino,” a forbidden being, and finds himself in a battle between gods and demons. There are more than 200 demons in Da’ath, including ones that will be familiar to series fans and newly drawn ones by Masayuki Doi, the game’s character designer. There will be demons as big as mountains and giant birds flying through the sky.
A limited edition for Japan called the “Forbidden Naobino Box” was revealed on the site too. It has “plenty of demons and music that embody Shin Megami Tensei V,” as well as an item resembling Naobino.
As for the release date, the website stated that Shin Megami Tensei V will launch on Nov. 11, 2021. Atlus Japan mentioned previously that it will have a simultaneous release, so that indicates that it will release in November in Western territories as well. A Nintendo Direct will air on June 15, so the official Shin Megami Tensei V release date announcement will most likely be there.