For 19-year-old Keiichi Yasunaga, the year 2050 lies somewhere beyond the visible horizon. It’s the era of his parents’ retirement, his own middle age, a period his generation tends to put out of mind — something to be dealt with later.

Yet, as the first quarter of the 21st century draws to a close, demographic shifts already underway are beginning to define the next 25 years. By midcentury, today’s teenagers will inherit a country transformed: a Japan with millions fewer people, an unprecedented share of older residents and a generational balance tilted in ways no society has experienced before.

“It’s hard for me to imagine what it will be like by 2050,” says Yasunaga, a senior in high school who plans to enroll at Tokyo’s Waseda University next spring. “I think AI will be at the center of our daily lives. I also think pensions will eventually disappear, and the retirement age will keep getting pushed back — to 80, or maybe even 90 in the worst case.”