Koiso’s Account of a Fuji Bank Employee was published in 1991. One of the earliest biographical accounts of the life of a Japanese Sarariman ("Salaryman"), it became a bestseller in the then popular financial scandal genre.[3] Patrick Smith, who interviewed Koiso, writes that he "broke the colossal silence of the corporate warrior" by recounting stories of "'coercive labor,' intimidating managers, corrupt union officials, executive suicides, karoshi incidents, 'service overtime' scams, vindictive personnel departments, and employees banished to various Siberias for being too independent of mind."[4][5]
Koiso, concerned about working conditions at the bank, rose to the top of the local union representation. This led to him being reassigned to isolated rural bank branches as punishment, although he earned the support of his branch managers. Corporate retaliation did not soften his views, as Koiso believes that "[t]his kind of contradiction—depending on internationally unacceptable working conditions to become an international company—cannot go on forever."[6]
Koiso also wrote other business books, including The Collapse of Japanese Management, (日本的経営の崩壊, Nihon teki keiei no hōkai) published in 1996 and Advice for a Proud Life as an Ordinary Employee, ( 誇り高き平社員人生のすすめ, Hokori takaki hira shain jinsei no susume) published in 2000.[2]