Both he and fellow Japanese star Masashi Ebinuma will be unseeded for the event at the German city’s ISS Dome.

High school colleagues, the pair have had a handful of contests on the national scene since three-time world champion Ebinuma moved up from under-66 kilograms to under-73kg after winning a second Olympic bronze medal at Rio 2016.

Their first clash on the IJF World Tour, which came at the Osaka Grand Slam in November, was a classic encounter.

Ono, 27, was the victor on that occasion, avenging an All-Japan Championships loss to Ebinuma, 29, from April of last year.

The five continents will be represented in Düsseldorf with 683 athletes from 97 countries registered.

Hosts Germany will be pinning their hopes on Dominic Ressel, the under-81kg gold medallist at the Paris Grand Slam earlier this month.

Ressel comes into the event on the back of the best result of his career and will be looking to better his bronze medal from 2018.

The 25-year-old can assume pole position in the race for next year's Olympic Games in Tokyo having blown it wide open in the French capital.

His team-mate Alexander Wieczerzak, the 2017 world champion at under-81kg, withdrew from the event on Tuesday (February 19) with no reason stated.

Initially a Grand Prix, the event in Düsseldorf was upgraded to a Grand Slam in 2018 for the first time.

"The IJF World Judo Tour 2019 gathers pace this month with Germany the location for our second Grand Slam of the month and third event of the season," IJF President Marius Vizer said.

2Germany is one of the most famous legs on the IJF World Judo Tour and Düsseldorf was upgraded to a Grand Slam last year as it attracts the world’s top judoka and has a well-deserved reputation for being one of the highlights of the calendar.

"Tokyo 2020 Olympic qualification is well underway with the Tokyo 2020 Olympic Games a little over a year away and all our judoka are giving their all with the hope of securing qualification and selection for the next Olympiad.

"Düsseldorf is a crucial stop on the road to the Games and also to the Tokyo 2019 World Judo Championships.

"Olympic and world champions will be in action in Germany and judo fans can look forward to a spectacular event."

German Judo Federation President Peter Frese added: "On behalf of the German Judo Federation, I would like to welcome you to the Judo Grand Slam in Germany.

"After 2018, we have the chance to host this amazing sports event in the world-renowned city Düsseldorf for the second time.

"Athletes, coaches and spectators can look forward to a perfectly-organised and exciting competition.“

"Since last year, the ISS Dome is the new home for the Grand Slam and the perfect place for this tournament.

"The new competition hall offers more space and perfect conditions for a sports event and the DJB is proud to welcome all the delegations in one of the biggest sports halls in Düsseldorf."

Watch the action on Judo TV.