 He took a distance double at the Japan Championships in Athletics and won a second 10,000 m title in 1991.He also competed on the roads, winning the Kosa and Nobeoka 10-milers in 1990, then having successive wins in 1991 and 1992 at the All Japan Corporate Team Half Marathon Championships, Beppu-Oita Half Marathon and Hyogo Relays 10,000 m.

Osano competed extensively around the world in the 1991 season.In May he had wins at the Great West Run in England, as well as at the Bay to Breakers and Bolder Boulder in the United States.