Inaba was born on September 23, 1964, as the second son of a family in Okayama. While music may have been his passion, he also wielded math as a strong point, at one time placing in the top three students nationwide. In 1987, Inaba graduated from Yokohama National University's Faculty of Education with a degree in mathematics; however, he soon decided that being a teacher came with too many restrictions.
Inaba's first recorded appearance as a vocalist came under the alias Mr. Crazy Tiger, recording for Burning, the solo album of Blizard guitarist Matsukawa Toshiya. His debut as a composer came shortly thereafter, writing a song for TUBE's Maeda Nobuteru's solo album, Feel Me.
Fate pushed Inaba to T.M. Network guitarist Matsumoto "Tak" Takahiro and in 1988, the duo debuted as B'z. While their first album, Nothing to Change, featured lyrics written by Aran Tomoko, Inaba has written the lyrics for every B'z release thereafter. With music influenced by established Western acts like Aerosmith and Led Zeppelin, Inaba and B'z soon reached superstar status.
From their 1990 single Taiyou wa komachi Angel, every new single by B'z has, as of 2010, debuted at #1. The series of successes saw both a rise in the pair's popularity and a distinct evolution in their style, progressing from synth-rock to hard rock to their blues phase in the mid-90s. Not content with B'z being a household name, Inaba soon opted to take both matters and music into his own hands.
Inaba's solo career was launched in January of 1997 with the album Magma. Despite having no singles attached to the release, the debut was a major hit, topping the charts much like the B'z releases before it. Inaba followed this with his first single, 1998's Tooku made, naturally hitting the top of the Oricon charts as well.
While the vast majority of his musical contributions has been through B'z, Inaba's solo work has still seen its share of popularity. His later albums, including 2002's Shian and 2004's Peace of Mind, both performed well, with live tours imitating the albums' success.
Inaba's international contributions have also been well-received, among them 1999's Angel Sky from Steve Vai's The Ultra Zone, and 2009's Sahara, a single included on the solo album of Guns'n'Roses's Slash. The latter would go on to win the Western Single of the Year award at the 2010 Japan Gold Disc Awards.
Save for the above international work, Inaba's solo career was put on hold in 2004. B'z, however, continued to flourish, releasing several albums amidst just as many lives. As testament to their popularity and longevity, the band also released its complete discography on iTunes, and in 2007 the duo was admitted into the Hollywood Rockwalk Hall of Fame.
After a six-year hiatus, Inaba resumed his solo activity in 2010. His long-awaited new single, Okay, was released on June 23, with the Koshi Inaba LIVE 2010 ~en II~ tour currently in its planning stages. Fans of the voice, rejoice: it's time to listen, again.
