Keiko obtained MA degrees from Osaka University, the University of Kent and SOAS (University of London). She holds a certified qualification from The Society for Teaching Japanese as a Foreign Language by the Japan Educational Exchange and Services. From 1998, she taught  Japanese language at various educational institutions, including Oxford University,  until retiring in 2022.

She founded Oxford Japanese School as a private tutorial group in 1999. Upon incorporation of the school in July 2019, she stepped down as headteacher as well as teacher, and she has since been serving as the chairperson of the Board of Trustees. Keiko also takes an active role as educational advisor, devoting herself to the further development of the school.