Kanakuri grew up in a rural town called Nagomi on the island of Kyūshū to a family that sold sake.

[3] In November 1911, at the age of 20, Kanakuri raced in the domestic trials for the 1912 Stockholm Olympics where he reportedly set a marathon world record at 2 hours, 30 minutes and 33 seconds, although the course was just 40 km (25 mi).

The Japanese team coach, Hyozo Omori, was mostly bedridden due to tuberculosis and failed to give Kanakuri sufficient pre-race training.

Throughout the race, dozens of competitors dropped out, including runner Francisco Lázaro, whose mid-race collapse and subsequent death made him the first Olympic fatality.

About sixteen miles into the race, an exhausted Kanakuri left the course and desperately stumbled into a nearby garden party, where he drank orange juice[11][nb 3] for an hour.

Sweden added Shizo Kanakuri to its missing persons list, and his name remained there for fifty years.

A Swedish reporter discovered him working as a geography teacher in southern Japan[12] and in 1967, Sveriges Television offered Kanakuri the chance to complete his marathon.

Immediately upon arriving in Sweden, he "jumped off the plane" and "jogged around the tarmac" to warm up his legs, and "showed great vigor" according to the Associated Press.