Nippon is the Japan analogue of the Warhammer Fantasy Battle universe. It is an archipelago nation to east of Cathay (of course). Also, "Nippon" is literally the Japanese word for "Japan", because of course.
Nippon appeared all the way up in the 1st edition of WFB, and can be considered one of the oldest created human factions, alongside Norsca and similarly abandoned Albion, some years before The Empire was introduced. It was a prominent faction in the first three editions, although due to the lore being less important in the Oldhammer and the lack of proper rulebooks at the time (no faction ones, all armies are in one book) Nippon never was really fleshed out. And then it was abandoned, and most of the lore was squatted.
Graeme Davis explains the squatting of Nippon like this:
The East was never officially opened up by GW. They stuck a toe in the water – after Kagemusha, the Shogun miniseries and the 80s fashion for Japanese characters on T-shirts, there was a lot of interest in feudal Japan among 80s geeks. There was the short-lived Oriental Heroes range, and the Perrys did a few ninja minis, but almost nothing in the way of text. I proposed an Oriental Heroes vs. Hobgoblins battle box (working title: Bakemono’s Revenge) but the battle boxes were dropped after McDeath. What Mark found is the mortal remains of the Tetsubo project. Dave Morris and Oliver Johnson, authors of the “Way of the Tiger” gamebooks, were commissioned to create a Nippon supplement for WFRP1. I was one of the people who looked over the original "manuscripts" when they turned it in, and everyone agreed it didn’t nail the WFRP tone. It was more like an adaptation of FGU’s Bushido to use WFRP1 rules. It languished in a “to be developed” pile for a long time, but nothing happened with it. As time went on it was getting harder and harder to get a green light for a new Enemy Within adventure, let alone opening up a whole new region. Then the fashion for Japanese stuff faded and that was that.
So, if you're wondering about Fantasy Squats, they're pretty much these guys.
Old Lore (pre-4th Edition)
Nippon is pretty much just a Tokugawa-era Japan with some minor fantasy stuff and only a little bit of somewhat good ideas. They were apparently united as a nation for the first time in 1IC by some guy named Yamayakyuki I who promptly dropped dead a few years later in 12 IC and since then the position of Emperor (known as the Divine Sun) has become mostly ceremonial similar to how the emperor position was in real life Japan during the Tokugawa Shogunate.
Nipponese (like other Oriental guys in Oldhammer) worship a Buddha-like deity known as the Orange Simca which was named after one of the Warhammer developers' car. The truly hilarious thing is that Simca isn't even Japanese brand, but a French one. Simcaism has a martial version called Vim-to, that is worshipped by crazy, but skilled monks and mages that fight with bare hands. There are also a bunch of Tsien-Tsin cults, which is not unusual for Eastern Lands.
The little official info on their land army pretty much shows it as being the same as what real-life Japan had during the latter half of the Shogunate (arquebus wielding ashigeru, peasant foot soldiers, samurai and ninja etc.) plus, rocket artillery, magic sorcerers, magic kung-fu monks and...suicide bombers called Kamikaze. Out of magical creatures, Nippon only got Ki-Rin and Temple Dogs, which were shared with Cathay.
There were almost no named characters in Nippon back then. "The tale of Sanyo Kawasaki" scenario told the story of a Samurai who had a butthurt over the fact that the government let a foreign ship pass near the Nipponese coat (not even landing there) and made no attempts to sink it. He gathered an army under the command of his retainers with similarly stupid names (Honda Suzuki, everyone?) and marched to the capital, but failed to take it and ritually killed himself. This was the only Nipponese scenario before the squatting happened, by the way.
Genevieve Sandrine du Pointe du Lac Dieudonné went there once. Probably. If she exists. Honestly, this wouldn't be worth mentioning except that we don't know shit about Nippon so it's like 5% of what we know.
Current lore (post-4th Edition)
Nippon is still the same old Tokugawa-era Japan, but less satyral and/or stupid and more... nothing. At least we know that there the Skaven learned how to be ninjas, right? Nah, not really, other lore states that Clan Eshin rats learned to be ninjas in Cathay. On a less stereotypical note, Ogres also apparently exist there somehow and are known as Oni, so you could probably convert some Ogre kingdom units in order to help support a homebrew Nippon army.
Warhammer Fantasy Roleplay 1st Edition (which almost got the Nippon supplement, by the way), states that there are three known characters from Nippon: Lady Katsui Okumoto, wife of the den Euwe merchant clan's leader in Marienburg; Toko and Masahito, a ninja and a bouncer in a service of Indan merchant. The last one is named after a real-life Japanese prince, it seems.
According to the End Times, they've got the best fleet ever, but they don't do shit with it. It's the best fucking fleet in the world. That's right, not druchii black arks or asur dragonships, fucking Yamato-Class Battleships.
This is literally everything we know about Nippon.
Andy Hall recently confirmed that they aren't planned Total War: Warhammer 3, so yeah, sorry...until the prototype combined map was found in the game files that included Ind, Khuresh...BUT NO NIPPON. Then again, they also said they wouldn’t do Vampire Coast and Andy also said that while the early plans for additional Total Warhammer 3 content is solidly planned out it get looser as it goes and nothing is strictly off the table so anything could happen.
It turns out that Nippon exists in an Immortal Empires Cathayan map prototype, and is even mentioned in the notes as a Kingdom of Nippon, severely downplaying the status of this nation, it seems. Will it also mean that new Nippon can probably use a different Japanese history era? Probably not, but we'll see.
|Regions and Areas of the Warhammer World|
|Areas of The Old World:||The Empire of Man - Bretonnia - Albion - Estalia - Tilea - Kislev - Norsca - Border Princes - Worlds Edge Mountains - Karak Eight-Peaks|
|Areas of The New World:||Naggaroth - Lustria|
|Areas of The Eastern Lands:||Cathay - Nippon - Ogre Kingdoms - Dark Lands - Kingdoms of Ind - Khuresh - Eastern Steppes|
|Areas of The Southlands:||Nehekhara - Araby - Badlands - Marshes of Madness|
|Other Areas of the world:||Ulthuan - Athel Loren - Chaos Wastes - Skavenblight - Lost Isles of Elithis|
|Main bodies of Water:||The Great Ocean - The Far Sea - The Sea of Dread - Inner Sea of Ulthuan|