Ishii, who is the youngest heavyweight Olympic judo champion of all time having claimed the over-100 kilograms title for Japan at the age of 21, now resides in Croatia’s capital and recently became a citizen of the country.

The former junior world champion, World Team Championships gold medallist and All-Japan Championships winner heard about the club’s work and phoned up its President Marina Draskovic to offer his help.

"When an Olympic champion calls you for a cup of coffee, you don't hesitate a single moment," Draskovic said.

"That's how our story with Ishii started.

"Simple, sympathetic, emphatic and humble – these are our first impressions of this Olympic champion who unselfishly came to our club.

"His question was, 'how can I help you and what else can I do for you'.

"This is not something that you often hear in any sphere of life and especially from someone of his calibre."

Ishii devoted himself to Fuji Project judoka with cerebral palsy.

He explained techniques for more than two hours and also did 30 minutes of randori, the primary method of learning the many lessons of judo, both with children from Fuji Project and non-disabled "pinky" judoka who usually help to carry out training.

"I held my first philanthropic activity in Zagreb as I wanted to contribute to Croatia because Croatia is the place I belong," Ishii said.

"I’m planning to do that kind of philanthropic activity in Serbia and Bosnia and Herzegovina.

"I don’t know how much I can help, but I will do my best."

The session received widespread media coverage in Croatia, a nation which has hosted an annual leg of the International Judo Federation (IJF) World Tour, a Grand Prix, since 2013 and will do so this year in July in Zagreb.

"For our judoka, Ishii is a living legend who gave them his most precious things, his knowledge and his time," Draskovic added.

"Dear Ishii, thank you from the bottom of our hearts.

"You created strong and powerful memories that will last for a lifetime."

In September, a Memorandum of Understanding to bring the IJF and the International Blind Sports Federation (IBSA) closer together was signed in Azerbaijan's capital Baku.

The IJF and IBSA jointly started a project with the aim of investigating the future integration of Para judo in the former.