Okuizumi was born in Mikawa, Yamagata Prefecture, and attended high school in Saitama Prefecture, before studying Humanities at ICU in Tokyo.
He completed a master's course at the same university, but dropped out midway through his doctoral course.
In 1993, he won the Noma Literary Prize for New Writers for the novel, Novalis no Inyō, and the Akutagawa Prize for The Stones Cry Out the following year.
The Stones Cry Out has been translated into a number of languages including English and French.
Okuizumi started working at Kinki University in 1999, and continues to teach there.