So here’s the current view of Japan, it’s not completely right because Kyushu is supposed to be smaller, but oh well.
Blue/the majority of Japan: The current Japanese Government. The largest faction present in Japan but they are overstretched and still reeling from economic devastation. Looking to making a comeback using New Fukuoka.
While they nominally have full control over their territory, the truth is most of their cities could be compared to Brockton Bay. The warlords below are simply the most visible.
Dark Red/Hokkaido: The New Japan Movement led by Nue, a very powerful changer. Not actively antagonistic but they believe that in areas where the Japanese government has failed they should step in to provide. Very Yakuza like.
Likely the most sensible of the warlord factions, but that's fairly relative. They're more than willing to murder, steal and create human trafficking systems within their territory.
Yellow/Shikoku: Mount Ooe faction led by Shuten-Douji along with her sister Ibaraki-Douji. Very militaristic and Xenophobic. Have outright tried to invade and steal land from the Japanese government by force before being repelled. Led primarily through the intense charisma of its leaders.
Purple/Okayama and Hiroshima: The Night Parade of one hundred demons or the Hyakki Yagyō led by Nurahiyon. A gang of Case-53's and other individual's that have been physically warped by their power. Notably they don't actually rule their land, they're more focused on their own hedonistic impulses. One day they may be roving through the countryside killing people horribly and the next they're learning painting. They didn't even pick the gang's name, they just fit the theme so much that everyone else started calling them that.
Pink/Yokohama: Nobody knows. Everyone who enters this territory drops dead on the spot. High level brutes can survive this effect but they have never found the parahuman causing this effect.
Naturally the Japanese Government is very concerned about how close this is to Tokyo, but they can't really do anything about it. The constant threat visible from their capital has done more to wound the credibility of their government than any of the three warlords could have accomplished alone.
Light yellow/ Okinawa: Minor warlord who has taken over the Okinawa islands. A master who can brainwash people if they ingest water he has touched in the last hour.
Light green/Kyushu: Unclaimed. For now.
Green: South Korea.
Orange: North Korea
Red: The C.U.I.