The 24-year-old is still training in Japan, which is currently in a nationwide lockdown after reporting more than 10,000 cases and 236 deaths. 

He has been driving from Osaka to Kyoto to train at a dojo owned by the parents of Ryutaro Araga, a fellow karateka who competes in the over-75 kilogram division, as reported by Kyodo News.

The pair are also joined by their sparring partners. 

Nishimura revealed he had recovered some passion for his sport as a result, despite the postponement of his home Tokyo 2020 Olympic Games, in which he was supposed to compete. 

"Now karate has become fun again," he said.

"What I've got to do doesn't change, I'm going to make every day special."

Nishimura's coach Kenichi Imai has also been visiting the dojo but is aware of the difficulties the lockdown has created. 

"The responsibility to train under the circumstances rests with the athletes, and coaches can't get involved," he said.

"They have to be sensitive about how they are seen by others and be careful not to become targets of public attack."

Nishimura earned a bronze medal at the 2018 World Championships in Madrid. 

He also qualified for Tokyo 2020 at the Karate-1 Premier League event in the Spanish capital in December. 

The Games have now been postponed until between July 23 and August 8 in 2021, however, due to the pandemic. 

Karate had been set to make its debut appearance at the Olympics. 

Numerous karate events, including Continental Championships in Europe, Oceania and Asia, are among those to have either been postponed or cancelled in response to the pandemic.

The World Karate Federation said it will continue to evaluate developments before deciding whether this year's World Championships can go ahead.

Competition, due to take place in Dubai from November 7 to 12, is currently due to be held as planned.