Issei Noro met bassist Tetsuo Sakurai in 1974 through a mutual friend, while Noro was a third-year student at Tokyo Metropolitan Tamagawa High School. The two became friends and started a band; on his mother's suggestion, Noro named it after the constellation Cassiopeia. With keyboardist Hidehiko Koike and drummer Tohru "Rika" Suzuki, they entered Yamaha's 1976 EastWest amateur music contest, reaching the finals, with Noro personally winning Best Guitarist. Casiopea made its recording debut in 1979, and Noro has served as its guitarist and main composer, with interruptions, ever since — through a 2006 suspension of activities and a 2012 restart.

In 1989, bassist Tetsuo Sakurai and drummer Akira Jimbo formed a side project, Shambara, with other musicians. Noro demanded the project be dissolved. Sakurai and Jimbo refused and left Casiopea instead, a rupture significant enough that it effectively ended the band's original lineup; they went on to form the duo Jimsaku in 1990.

Nearly two decades later, in 2008, Noro formed his own band, Inspirits, releasing its debut, Inner Times, that February. Akira Jimbo — the drummer whose 1990 departure traced back to Noro's own demand — joined Inspirits as a member, a genuine reconciliation between the two musicians documented in shared band membership rather than left as an old grievance.

Noro has released six solo albums and a compilation across a recording career spanning the 1980s to the present, including Sweet Sphere (1985), South Pacific Ocean (1993), and Under the Sky (2001) and Light Up (2002), both featuring drummer Noriaki Kumagai.

As Casiopea's main composer, Noro's guitar writing largely defined the melodic, technically polished sound that made the band one of the two or three most commercially significant Japanese fusion acts of its era, alongside groups like T-Square.