[1] Born in Ōta, Tokyo, Kawahigashi was raised in a family where his father worked for an oil company and his mother was a teacher at a Kumon learning centre.
During his years as an undergraduate, he worked for ASCII and authored several bestselling software books, supporting himself through royalties.
He then went on to study at the University of California, Los Angeles in 1985 under the supervision of Masamichi Takesaki, a proponent of the Tomita–Takesaki theory.
[3] According to Kawahigashi, his most notable achievement so far is the completion of the classification theory for local conformal nets with central charge less than one, co-authored with Italian mathematician Roberto Longo in 2004.
[6] Kawahigashi believes that one should never stop questioning, researching, or consulting others until complete understanding is achieved, asserting that 'It is absurd for someone who cannot do this to be in a doctoral programme.