When I lived in the Japanese countryside 10 years ago, I rarely came across other non-Japanese residents. Even in Tokyo, as a tall, white American, I’d sometimes get surprised glances from local residents.

But when I visited last month, I was struck by how much had changed. Hotels, shopping centres and cafés seemed to have at least one immigrant working there. Some of the young people staffing reception desks and video game arcades wore badges with non-Japanese names.

At one pub-restaurant in Kanazawa, a mid-sized city north of Tokyo, I saw a young Caucasian assistant behind the counter assisting the sushi chef. At another restaurant, we were served by a non-Japanese waiter from an Asian nation – and ended up communicating in English.

In short? Japan is internationalising – and this process is on the cusp of rapid acceleration.

The driving force is demographic change: Japan’s population is ageing rapidly and shrinking. Add in other factors including never-before-seen levels of foreign tourism, plus massive preparations for the 2020 Tokyo Summer Olympics, and the result is a nation that desperately needs more workers to fill jobs.

Japan has been aware of a looming demographic crunch for decades, but because successive governments have been reluctant to take major steps, the problem has become more urgent.

Prime Minister Shinzo Abe wants to bring in more foreign, low-wage workers. But his proposal to accept hundreds of thousands of people to fill blue-collar jobs by 2025 is highly controversial in a nation that has traditionally shunned immigration.

On Saturday, Japan’s parliament accepted that proposal in a contentious and unprecedented move to let in more immigrant workers than ever before – 300,000 throughout the next five years, starting in April. The new bill comes at a time of historic change in Japan. And how everything shakes out could shape the country for generations.