Hiroko Katsuragi knew that Rinngo Sheena was special the second she laid eyes on her. The co-editor-in-chief of Oricon, Japan's weekly music-industry bible, Katsuragi sees or hears hundreds of new pop-star hopefuls every year. Most fail to make a lasting impression. Yet Katsuragi still remembers the day in 1998 when she watched Sheena's first-look videotape. Though the demo was short and shoddily made, Katsuragi was mesmerized by the then 19-year-old prodigy's presence. "I was instantly drawn into her world," she says.

Five years later, many more have been drawn into Rinngo Sheena's world. Though Japan's music industry has long been the world's second largest, it has also been something of an artistic wasteland. Barring significant exceptions, the most popular acts over the past few decades have been indistinguishable pretty faces warbling cookie-cutter tunes produced by a handful of Svengalis. That's been changing recently, however, as more rock acts are taking advantage of the recent slump in the Japanese music business (and the teetering faith in old formulas that decline has caused) to assume greater control of their careers. They're taking more risks and are recording some of the most personal, vital and creative pop music the country has ever heard.

The trend's most striking manifestation may be Rinngo Sheena, a singer-songwriter who has, over the past five years, become a leader in pushing the boundaries of Japanese rock and, in doing so, has achieved mass-market success. Though only 24, Sheena has developed into an artist with surprising maturity and depth, one who manages, like Björk (the Western musician to whom she is often compared) to retain her hipster alternative cred while still being a bona fide mainstream hit.

Growing up in what she describes as a strict household in the city of Fukuoka on Japan's southern Kyushu island, Sheena started taking piano lessons at age 4. "I wanted to start lessons even earlier than that," she says, "but my mother decided that four was plenty early enough." By high school, she had played in several bands and was writing and singing her own songs. The diverse list of influences she names off the top of her head includes Ella Fitzgerald, Kurt Cobain, Edith Piaf and Japanese balladeer Eiko Shuri. In 1998 she signed with Toshiba EMI records. That's when Oricon editor Katsuragi met her. "She carried around business cards from the record label with her name on it," Katsuragi recalls, "which is odd, because artists usually don't do that, not even new ones. It was funny and sweet."

With the release of Sheena's first singles and her 1999 debut album Muzai Moratorium, listeners discovered her music was anything but funny and sweet. Most fresh-faced singers are still expected to be prim and practically virginal, but Sheena's songs demonstrated an often controversial, darkly sexual edge from the beginning. Like Liz Phair, a U.S. phenom of the early 1990s, Sheena pointedly contrasted her clean-scrubbed good looks with the raunchiness of her lyrics. In her breakout hit Queen of Kabukicho, for example, Sheena sang as the daughter of a prostitute following her mother's descent into Tokyo's most notorious red-light district. Not long after, she followed up with the hard-edged Honno. The video to that song caused a sensation due to its raw, sexual imagery: dressed in a tarty nurse's outfit, Sheena tears up a doctor's office, smashing panes of glass with her fist, elbow and heel and gets intimate with a female patient. In interviews at the time, she said Honno (the word means instinct) was intended to show that women had as much right to erotic fantasies as men.