Shouzou Kaga worked at Intelligent Systems from 1990 to 1999, after which he left the company to form his own studio, named Tirnanog.
While working at Intelligent Systems ,Kaga worked on Fire Emblem: Ankoku Ryū to Hikari no Tsurugi, Gaiden, Mystery of the Emblem, Genealogy of the Holy War, BS Fire Emblem and Tharcia 776 in 1990, 1992, 1994, 1996, 1997, and 1999 respectively. Kaga also assisted in the development of Super Famicom Wars in 1998.
At Tirnanog, Shouzou Kaga developed Tear Ring Saga, and Berwick Saga in 2001 and 2005 respectively.
Shouzou Kaga has recently worked on an doujin SRPG called Vestaria Saga: The Seven Sacred Rings.