This is the Japanese Apocalypse that you all know so well. It needs no explanation, does it? It includes subsequent sequels and Gaiden, including Persona.

A world in which the whole of Japan has become 1970s Australia.

Japan as Russia.

A world in which Japan is divided into northern and southern Japan and is in a state of civil war.
A game with a worldview like Philip K. Dick's The Man in the High Castle cooked up with old-fashioned fictional warfare like Gundam 0083.

Japan, where the justice system has collapsed even further than in reality.
A world where the principle of presumption of innocence and due process of law have completely disappeared and judiciary is abused.

A world in which the entire surviving human population became beast-eared/kemono-mimi after the fall of modern civilisation.
The place where the protagonist wakes up at the beginning of the story is actually Yamagata ken/Prefecture.

A world in which the medical field has collapsed.

Japanese stock rates collapse.
Black Monday every day.

"Kyoto has become an Akutagawa Ryunosuke-like world."
"Kyoto has been a Rashomon-like place since ancient times, so there are no surprises."

USA in the Japanese brain.

1995, 1.17
2011, 3.11

suggest from letshugbro
A world in which the whole land has become Gunma ken/Prefecture.※
焼肉定食, wrong. 弱肉強食 -- law of the jungle.

※ On the Japanese-language internet, Gunma Prefecture is famous for being the subject of jokes. Comments by Japanese politicians on the internet meme, 'Gunma, an undeveloped area'.
Masaaki Osawa, Governor of Gunma Prefecture
"Gunma Prefecture is 2/3 mountain forests and scenic land, so depending on how you take it, it may be an undeveloped area. Nice words."
Yuko Obuchi, Member of the House of Representatives (Gunma 5-ward)
"Wouldn't it be nice if you could feel like Africa just 100 km from Tokyo?"