Ichiyama joins the squad after winning the Nagoya Women's Marathon in a race record time of 2 hours 20min 29sec.

She pulled ahead after 30 kilometres and ran uncontested to the line on a rain-soaked course.

"I ran like I expected I would," the 22-year-old said to Kyodo News.

"I think that the real race started after 30 kilometres, and even though I was alone I was able to finish like I had practiced."

Only elite athletes ran in Nagoya due to the outbreak of coronavirus.

Osako secured his place in the men's team at the Olympics because no runner at the Lake Biwa Marathon could beat the national record time of 2:05:29 he set at the Tokyo Marathon on March 1.

Shogo Nakamura and Yuma Hattori had already been named to the men's team, while Honami Maeda and Ayuko Suzuki had previously been selected in the women's squad.

All four qualified through the Marathon Grand Championship in September, which doubled as the Japanese trials.

The Nagoya Women's Marathon and the Lake Biwa Marathon were the final selection races for Japan's team.

Both the men's and women's marathons at Tokyo 2020 will be held in Sapporo, which lies more than 800 kilometres north of the capital.

This is due to fears about high temperatures in Tokyo.