The Japan of Earth Bet was a nation in shambles, considered ground lost to the Endbringers in their war on humanity. It was dependent on international assistance. It no longer has many dedicated heroes, on the other hand wildlife in the destroyed area has seen a resurgence.
Leviathan attacked Kyushu on the night of November second and the morning of the third, 1999. Nine and a half million were killed, and nearly three million evacuees rendered homeless. Japan never recovered. 
According to rumor, Black Kaze snapped after Kyushu was destroyed. Whatever the reason, she roamed the landscape, killing indiscriminately, until she was captured and sent to the Birdcage.The Guild recruited Masamune from the ruined area of Japan, where he had been living as a hermit.
↑ 1.01.1An Earth where Japan was in shambles, a different president led the United States of America, there were a thousand times the number of parahumans, and Endbringers threatened to crush humanity in a merciless, unending battle of attrition. - Migration 17.3
↑ 2.02.1The world waited to see if Brockton Bay would become another Switzerland, another Japan, another region that simply couldn't recover. Ground lost to the Endbringers in their relentless campaign of attrition against humanity. - Interlude 13
↑Japan isn’t a world power and it’s still dependent on international assistance 12 years after Leviathan’s visit to Kyushu. - Comment by Wildbow
↑ 4.04.1Behemoth had come from deep underground. Leviathan had emerged from the ocean. The Simurgh had approached from the far side of the moon and descended to hover just above the tallest building in Lausanne.
The fourth, it seemed, was appearing in plain sight.
"There's no heroes on scene," Tecton said. "Japan doesn't have many dedicated heroes anymore." -Scarab 25.4
↑Well, you could say that there isn’t ‘Japan’ as a country, what with the ramifications of the Kyushu attack, but the island with its flora and fauna is basically still there. - Excerpt from Monarch 16.9
↑►Laotsunn (Kyushu Survivor) Replied on July 7th, 2011: Better arrested or banned than dead. I'd say death is the thing to worry about here. - Excerpt from Interlude 19.y
↑There was no guarantee they wouldn't use Dodge's technology to visit the United Kingdom or Africa or even shattered, half-sunken Kyushu. - Interlude 26.x)
↑ 8.08.1Masamune wasn't present, but from what I knew of the guy, he wasn't even close to being a front-lines combatant. They'd recruited him from the ruined area of Japan, a somewhat crazed hermit, and gave him work in figuring out how to mass produce their stuff without the maintenance issues snowballing out of control, like tinker tech tended to do in large quantities. - Sting 26.2
↑ 9.09.1Black Kaze. A Japanese urban legend that had turned out to be too real. Word was she'd snapped after Kyushu was destroyed. Except she'd remained lucid throughout trials, calm, patient. Nobody knew her real body count, but conservative estimates put it in the tens of thousands. She'd roamed the remains of the landscape, killing survivors, killing rescuers, boarding the ships that approached too close to the ruined area and killing the crews, and rendering a widespread area devoid of life. - Extinction 27.3
↑I wouldn't mind a system like the Yakuza of Japan's yesteryear, where we support and involve ourselves in local business, legally, to the point that nobody will be able to shake us." - Queen 18.4
↑"Kyushu, the night of November second and the morning of the third, 1999. His sixth appearance. Nine and a half million killed when the region was swamped with tidal waves from every direction while Leviathan disrupted prearranged evacuation attempts. Nearly three million evacuees rendered homeless, a nation sundered. - Extermination 8.2
↑Japan hit. V. little left. Most evacuated. 22m est. dead. Total est. toll 500m. "PRT issue phone," Sophia commented. "Newer model than the one I had." - Extinction 27.3