The rivalry between China and Japan has been pushing swimmers on both sides to train harder heading into the 2020 Tokyo Olympics.

At the 2014 Asian Games in South Korea, Japan's Kosuke Hagino stunned China's heavily favored Sun Yang to snare gold in the 200m freestyle.

Hagino then led Japan past China to finish first in the 4x200 free relay, stoking what Sun later described as a "healthy motivation" for both sides.

After losing to Japan again by 0.28 seconds in the 4x200 free relay at the Asian Games in Jakarta in August, Sun said to outperform the Japanese on their home soil in 2020 is the "ultimate goal" of Team China.

The rivalry intensified at the Asiad, with China and Japan each winning 19 gold medals and 38 of the 41 golds up for grabs.

To prepare for the Hangzhou meet, last month a group of Japanese swimmers, including national 50 and 100m free record holder Katsumi Nakamura, flew to Kunming, capital of southwest China's Yunnan province, to improve their aerobic endurance at a high-altitude camp－a training method Team China routinely adopts for major meets.

"The Japanese team appears very ambitious to dominate the pool at the Tokyo Olympics, which actually helps fire up our athletes to prepare to their best as well," said national team manager Cheng Hao.

"We are confident we will live up to the challenge and we will try to beat our opponents in all our strength events."