Ito began his career at Kiyonori Kikutake and Associates after he graduated from Tokyo University in 1965, going on to found his own architecture firm in 1971.
For the past 25 years he served as Senior Research Scientist at ETR Associates in California, USA. Over his professional career, he published the most definitive systematic reviews on the effectiveness of sex, relationships and HIV education in schools and is widely recognised as the leading world expert on sex, relationships and HIV education curriculum standards.