For millions of Japanese music fans in the 1990s, Namie Amuro wasn’t just the Heisei Era’s defining pop star, she was someone they grew up with.

This relationship is clear in the year-long documentary series, “Finally,” which has been streaming on Hulu since the 40-year-old star announced plans last year to retire from the entertainment industry on Sept. 16, 2018.

It follows Amuro as she navigates her farewell from J-pop, moving from a mall talk session to a radio appearance to her final stadium tour. And at every stop are her fans, squished together to scream and cry one last time for their idol. They are a diverse crowd, but mostly women, the majority seemingly in the same age range as the pop star herself, some with toddlers in tow.

The adoration surrounding this 12-month victory lap is well-deserved. Amuro’s story is also the story of J-pop. She set the template for what a Heisei superstar could be, and harbored global ambitions that, in the 1990s, didn’t seem unrealistic. Using her platform as one of the nation’s best-selling solo acts, she embraced a variety of sounds (some of them rather offbeat) up till the end of her career, smuggling all sorts of musical genres into mainstream Japanese pop.

Amuro’s childhood makes for a tear-jerking first act of a story. Raised in Okinawa by a single mother, she sang on local television and commuted 90 minutes each way to go to a dance school in a mall, which she could only attend with the help of financial aid. This led to her joining an idol group dubbed Super Monkey’s. Soon enough they became Namie AmuroWith Super Monkey’s, the group finding success with the then-on-trend sound of Eurobeat.

However, the path was set for Amuro to be J-pop’s breakout with an assist from the producer who helped define the decade’s sound, Tetsuya Komuro. “J-pop” is marketing copy — short and snappy. It entered the lexicon in the early ’90s, a deliberate branding shift from kayōkyoku(standard Japanese pop from before 1989). You can’t sell something overseas with a name like that, and J-pop wanted to go abroad.

Group acts proved most popular in early Heisei (1989 to present day), and some of the biggest used Komuro’s dance-pop to climb the charts. But Amuro gave J-pop its first solo superstar.

Starting with her debut single, 1995’s driving “Body Feels Exit,” Amuro went on a tear through the charts, including a run where most of her singles sold over a million copies. The absolute crest came with the 1997 wedding ballad “Can You Celebrate?” That one remains the best-selling song by a solo female artist in Japan, but still only offers a snapshot of her sound.

Amuro and Komuro were all over the place in the ’90s, from twinkling dance-pop to rock-dance hybrids. Digging into her albums only reveals stranger twists; her debut LP with Avex, “Sweet 19 Blues,” was briefly the best-selling album in Japanese music history, meaning a lot of people heard a nearly nine-minute “Latin House” rework of “Body Feels Exit.” Nobody asked for it but millions still listened, and that’s beautiful.

A generation-defining pop star serves as something of a canvas for fans and society. Amuro was, for the most part, a pretty ordinary person. Her lyrics focus on love and becoming a woman — resonant topics, but pop cliches — while interviews from this period stress her professionalism and maturity. Yet she became the avatar for Japanese youth culture in the ’90s. She never set out to be a fashion icon, but entire words were invented to describe her impact on the field. Her surprise pregnancy and shotgun wedding was applauded by the media. Her 2000 track “Never End” was commissioned by Prime Minister Keizo Obuchi for the G8 Summit in Amuro’s native Okinawa, leading to her singing it for U.S. and Russian presidents Bill Clinton and Vladimir Putin. Most pop acts are lucky if they can get a commission from an ice cream company.

Okinawa benefitted immensely from Amuro’s star power. Her relationship with her home has always been loving (she speaks highly of the islands in a 1990s TBS documentary) but somewhat detached (“If I had really strong feelings towards Okinawa, I wouldn’t have gone to Tokyo,” she told Time Magazine in 2000). She came closer to repping Jamaica on her reggae tune “Me Love Peace!!”

Yet her rise — and her decision not to play down her roots — transformed the general perception of Okinawa from backwater military plot to cultural treasure chest. Okinawan pop soon experienced a boom thanks to groups like Speed and Max (the Super Monkey’s, re-branded), which carried into the 2000s. When Amuro expressed condolences at the death of Okinawa Gov. Takeshi Onaga earlier this year, netizens went wild, seeing the move from the apolitical performer as either a defense of Okinawa or an anti-Japan provocation.

There’s no denying, however, that Amuro’s biggest impact was on Japanese music. She ushered in a final golden era of sales in Japan, one in which people would spend a lot of money on CDs, while plotting a new route to success via Asia, one that other Japanese acts would build on and that Korean pop groups would master. She allowed a new generation of women to take center stage in Japan, from Misia to Hikaru Utada to Ayumi Hamasaki.

Yet she kept exploring different sounds, drifting away from Komuro’s dance-pop in favor of R&B and her self-coined “hip-pop.” Amuro used her status to give shine to young Japanese rappers via the Suite Chic project, and her perseverance paid off with a late-career revival, kicked off by 2007’s springy “Baby Don’t Cry” and carrying on into recent years, where she delivered soaring ballads and even a collaboration with digital pop star Hatsune Miku.

And now she’s stepping away following a well-earned farewell tour. A large part of the hoopla surrounding Amuro’s retirement is due to nostalgia. She announced her departure before the Emperor did, giving many a preview of the Heisei Era’s inevitable conclusion and jump-starting a melancholy look back on the ’90s. And for many Japanese, Amuro has been a constant, from childhood to adulthood, defining the soundtrack to their lives. It’s usually a cliche, but in this case it’s safe to say her retirement is the end of an era.