Throughout 1981, Hirotaka Izumi appeared as a session keyboardist in J-Pop albums by singers Junko Mihara, Mayuki Masaka and Naomi Akimoto, to name a few.

In 1997, he released his first solo album Forgotten Saga, and with it, became concentrated on playing piano, and left the group with the "Farewell & Welcome" tour the following year.

In the same year, guitarist Yuji Toriyama formed a band with drummer Akira Jimbo and Izumi, calling themselves Pyramid.

According to the Misty Fountain Hirotaka Izumi blog, the trio disbanded in the summer of 2010 and was restarted in October with bassist Komobuchi Kiichirou and drummer Masaharu Ishikawa.

On April 28, 2021, it was announced on the official website that he died of acute heart failure, with his funeral held only by close relatives.