Sen Genshitsu, a would-be kamikaze pilot who became a Japanese tea ceremony master preparing cups of matcha for world leaders and monarchs, died aged 102 on Thursday, reports said.
With a motto of "peacefulness through a bowl of tea", Kyoto-born Sen used ancient "Urasenke" tea tradition rituals to spotlight his anti-war messages.
The United Nations headquarters in New York and the USS Arizona Memorial in Pearl Harbor, Hawaii -- the scene of a devastating Japanese attack that brought the US into World War II -- were among the locations for his ceremonies.
His death was reported by major Japanese media, including the national broadcaster NHK and the top-selling newspaper Yomiuri Shimbun.
AFP could not immediately reach the Urasenke school for comment.
Born in 1923, Sen went through training as a young man to become a kamikaze pilot in World War II, but the fighting ended before he had to carry out a suicidal mission.
He later told how he used to serve tea to his fellow soldiers during military training.
In a 2023 interview with NHK, Sen stressed the calming effects of tea culture.
"A bowl of tea makes spirits very peaceful. When everyone is peaceful, there will be no war," he said.
An ordained Zen monk, Sen became the 15th-generation grand master of the Urasenke school in 1964 following the death of his father who had previously headed the tradition.
He offered tea to monarchs and presidents including Britain's Queen Elizabeth II and Soviet leader Mikhail Gorbachev, and counted the former US secretary of state Henry Kissinger and former Chinese president Hu Jintao as friends.
He said that his wartime experience had helped shape his views on the importance of peace.
In 1997, he received the Order of Culture in Japan and in 2020, he was given the Legion of Honor, France's most prestigious order of merit.