Write an realistic, plausible alternate history scenario set on the world of the alternate history scenario with no references to the real world, OTL, or even to the fact that this is an alternate history scenario after all in the form of a lengthy, descrptive, exposition-filled real documentary history book chapter set in the world of the alternate history scenario, in which Japan, which [Japan] continued on its [Japan’s] post-WW2 growth towards [Japan] becoming a political, economic, military and cultural superpower [Japan], [Japan] never experiencing “the Lost Decade” and or the Plaza Accords or any slump in growth and development in the late 1990s and 2010s, [Japan] has Taiwan and the Pengu Islands returned to it [Japan] as a province [of Japan] in a repeat of the return of Okinawa in 1972 to Japanese control due to the Han nationalist, Han supremacist, Chinese nationalist, Chinese imperialist, Marxist-Stalinist political party/militant group/secret society of the KMT/Kuomingtang and the joint American-Soviet satellite state the KMT ruled with an iron fist, the Unitary, adhering to Sun Yat Sen's three principles of the people, nationalism, democracy and socialism [social welfare] one-party ruled and dominated directorial republic under a military dictatorship of the Second Republic of China/Nationalist China/National Government of the Republic of China which [Nationalist China] had [Nationalist China] been in exile on Taiwan in 1949 after the latter [the KMT and Nationalist China] lost the Chinese Civil War of 1947-1949 to the de jure Marxist-Leninist, socialist but de facto Han nationalist, Han supremacist, Chinese supremacist, Chinese Imperialist Chinese Communist Party ruled de jure socialist republic but de facto Han nationalist, Han supremacist People's Republic of China ruling [the PRC] over Han China, Guangdong, Guangxi, East Turkestan, Inner and Outer Mongolia, Tibet, Shanxi and Yunnan from [the PRC's stronghold and home base] Greater Manchuria, [Nationalist China] reunifying with the mainland after the death of the KMT's most infamous head, Nationalist China's most infamous Chairman and Generalissmo and Soviet dictator Josef Stalin's man in China, the Han Chinese revolutionary turned warlord  Jiǎng Jièshí, who [ Jièshí] was [ Jièshí] better known as "Chiang Kai Shek" in [when [ Jièshí/"Chiang" died]   5 April 1975 

with Japan subsequently restoring the Japanese province on Formosa on Taiwan and the Pengu Islands after their [Taiwan and the Pengu Island's] return to Japanese control. 

In order to get money to prop up the failing Soviet economy and also as a unimplied non-aggression treaty, the Soviets also return Sahlakin and the Kurils to Japan, with the Japanese subsequently restoring the Japanese province of Karufuto on Sahlakin and the Kuril Islands. 

After pro-democracy, anti-military dictatorship protests in the joint US-PRC puppet state of the totalitarian military dictatorship of the Republic of Korea occupying South Korea spread to the Soviet satellite dictatorship of the Korean nationalist, Korean supremacist, Leninist-Stalinist Worker's Party of Korea-ruled totalitarian communist dictatorship of the Democratic People's Republic of Korea occupying North Korea, [the protests in the ROK spreading to the DPRK] toppling both post-WW2 Korean regimes [the DPRK and ROK], the Soviets and Americans jointly agree to return all of the Korean peninsula to Japan in a repeat of the Taiwanese and Okinawan situations.

After the return of the entire Korean peninsula to Japan, the Japanese restore the Japanese province of  Chōsen on the Korean peninsula.