"Japan often feels like a country that rushed to embrace an exciting high-tech future decades ago, and then abruptly stopped when boom turned to bust in the 1990s, leaving islands of older technologies like stranded relics...

There is the Japan of bullet trains and humanoid robots. And there is the Japan of printed documents, humming faxes and an economy still largely dependent on cash. Its bureaucracy lives with at least one foot in the past, with a deeply ingrained desire to do things as they have always been done."

"I cannot help but feel that changes are slow in Japan. There are challenges that have been on the table for decades and left unresolved, notably an outdated approach to work and a lack of gender parity. As a result, economic growth has stagnated. The resistance to change is seen often in Japanese organizations, where the preference for seniority and lifetime employment remain strong, and there is less freedom to move away from these tendencies, especially compared to Western countries."

"In a country where warehouse workers use mechanized exoskeletons to lift heavy packages and a chart-topping pop singer is a hologram, many in Japan are frustrated and perplexed by the government’s insistence on using old technologies for a wide range of bureaucratic tasks."

What Hatsunia is:
The First Sound of Tomorrow is a worldbuilding project centered around Hatsunia, a futuristic Japan-like country that is more technologically advanced and socially progressive, with a less aggressive past.

An internet saying goes, “Japan has been living in the year 2000 since 1980,” meaning that Japan used to be a technological leader, but fell behind after the software revolution.
On the other hand, Hatsunia is still decades ahead in technology, and was partly inspired by a personified software whose name means "the first sound of the future."

Hatsunia's post-modern tech level (PMT) reflects the exaggerated (and sometimes parodied) high-tech reputation of Japan.
It is also inspired by Japanese Y2K futurism (such as the prediction of space hotels by 2020) and Frutiger Aero aesthetics.

What Hatsunia is not:
a country that is only about anime

"Isn't this just how weebs expect Japan to be?"
At first glance, it definitely looks that way. But there is a purpose to this.

"Weeaboo" originally referred to the kind of person who idealizes Japan for the anime/pop culture, while ignoring the social issues there. Of course, there's more to a society than anime.

Anti-weeaboos often point out Japan's problems. "There is institutional xenophobia and sexism." "The work culture is oppressive and inefficient." "I might visit Japan, but I would never live there."
In the 1980s, people expected that Japan would economically take over the world. Now, people complain that the Japanese economy is outdated and uncompetitive.

Aside from the Miku theme, the Hatsunia project asks:
What would really make a society like Japan more desirable to live and work in? What if the society could be less xenophobic? What if workplaces were more tech-savvy, and less toxic?

The less-dystopian cyberprep setting of Hatsunia was also made to counter the 1980s "yellow peril"/"Japan-bashing" undertones found in some cyberpunk media.
It is not meant to be perfect and free of all problems, but is similar to countries that rank highly in areas like gender equality, technological innovation, or general well-being.

Summary
(Disclaimer: This is pseudo-alternate history without a true point of divergence, and is not meant to be strictly plausible.)

The history of Hatsunia mostly parallels Japan up until the early modern era, with an earlier end to the feudal military dictatorship (shogunate). Instead of following a mostly-isolationist "sakoku" policy or trying to conquer Korea in the 1590s, the government adopts a non-interventionist policy, in which it engages in seafaring trade around the world (which is also encouraged by the island geography) but doesn't colonize anything either. With more foreign contact, xenophobia slowly becomes less entrenched in society. Instead of militant feudalism abruptly transitioning into a modern society in the 19th century, a more gradual transition is had.

Social reform movements and protests in the 18th and 19th centuries lead to the development of a modern constitution in 1868 with less feudal baggage, and a civilian-controlled military. Western-style democracy is emulated, but not blatant colonialism as they don't want to invite rebellions and a war with other great powers (however, they still want to expand influence through indirect means). The only exception would be the purchase of Micronesian islands from Spain in the late 19th century. The constitution theoretically grants equal rights to minority groups in Hatsunia, although they are not properly enforced until civil rights movements gain traction in the 1960s. Natural resources are gained through trade rather than annexation and oppression, which averts all the resentment people would have had.

Because the ideals of democracy, liberty, and social equality have stronger roots, Hatsunia does not descend into militarism during the Great Depression. It joins the Allies during WWII against an Axis China, and leaves the war mostly unscathed. After the war, the Mutual East Asian Cooperation Union is formed, becoming a sincere version of the so-called "co-prosperity sphere," and reflecting a more globalized and less insular outlook.

An information technology industry forms in the capital city of Miraikyo, known as the "Silicon Metropolis." Without having to recover from embargoes and nuclear bombings, and without post-war restrictions, Hatsunia can invest more in electronics and aerospace technologies, including more practical robotics systems. English is made an official language in 1967, which benefits the burgeoning IT industry as early computers are not powerful enough to handle kanji.

Today, Miraikyo develops the latest in software, personal computers, and smartphones, and its companies are globally competitive. However, the country has had to deal with the consequences of increasing privatization and inequality since the 1980s, and the government has recently taken more steps to regulate them. Government and private services have mostly become paperless (no hanko required, just digital signatures), and the cybersecurity minister is more knowledgeable about computers. One advantage Miraikyo has over Silicon Valley is that it isn't afraid to build higher density housing. The growth of the tech industry has encouraged the construction of a few arcologies, such as the Sky Mirai Tower.

In the 1960s, Hatsunia is not a leader in the space race, but doesn't have a late start either. As Hatsunia's economy reforms and becomes more digitized and connected to the rest of the world, a fully reusable heavy launch system called Mikumaru (in a similar role to this) is able to be developed in 2007. It enables a low-cost revolution in space access, with the first humans landing on Mars in 2016, and space hotels and lunar bases being built by 2020.

Work culture in Hatsunia is based on merit, innovation, and productivity instead of rigid hierarchies with seniority, strict adherence to outdated traditions like fax machines, and overwork. Social institutions also have a greater emphasis on racial and gender equality (thus attracting more foreign talent and supporting higher fertility rates), although some bigotry still exists (as it is an issue in every country). There is also a balance between individualism and collectivism.

"Hatsune Miku, due to her nature, tends to attract those who are tech savvy. Myself included. Shoutout to fellow tech-savvy Miku fans!"

"Since living in Japan the reality of day-to-day life isn’t really any more tech or futuristic than it is in any other developed city or country. But in my photography, I try to create the illusion that it is some kind of digital future world that lives up to my childhood expectation of the place."

"Going digital is a global trend in such places as the United States and Europe. If Japan continues to stick to traditional practices based on paper and hanko [personal stamps], I think it won’t be able to do business internationally."

"Silicon Valley attracts talent from around the world, whereas Japan keeps tight limits on immigration... 'To get some sense of the impact of immigration in high tech, imagine what would happen to Silicon Valley if every U.S. tech company fired all their foreign-born workers,' said [David] Weinstein, who teaches about the Japanese economy. 'U.S. leadership would collapse.'"

"What is Cool Japan? Manga, anime, Japanese food — cool, but hardly the economic lifeblood of a nation whose cutting-edge technology, world-leading research and fierce work ethic could be setting the world on fire.

By 2050 cars will be driving themselves; 3-D printers will be coughing out products as blithely as 2-D printers today cough out words and phrases; robots will be doing so much for us that we risk finding ourselves with nothing to do for ourselves — and Japan to be stuck in manga- and anime-land instead of leading this charge into the future?"