"It's really fulfilling to tackle a truly classic song with a beautiful melody; just to merely touch a song like that feels wonderful," says Shiho Ochi, better known to her legion of fans as J-pop soul diva Superfly, as we chat in her record company's Tokyo office.

Released this week, her 10th single, "Wildflower," comes backed with a 15-track covers CD, compiling her versions of time-honored soul and rock 'n' roll songs that were included as B-sides on previous singles (usually as the third track) or recorded live. Because of the inclusion of this second disc, the single will be counted by Japanese chart compiler Oricon as an album, and is almost guaranteed to follow her self-titled 2008 debut and 2009's "Box Emotions" to the No. 1 spot.

Perfectly echoing her 1960s- and '70s-styled music, the giggly 26-year-old's flower-child fashion has helped fuel a revival in hippyish headbands and ethnic one-piece dresses, as a short wander around Tokyo youth district Shibuya will attest. Her own line of clothes, Cosmic Market (produced in collaboration with fashion brand A.I.C), has cemented Ochi's position as one of modern music's most unassuming trendsetters. But it is her powerful voice and dazzling vocal range that have won Superfly respect from critics and fans alike.