The Duke of Cambridge looked momentarily uncomfortable as he swiftly corrected himself, saying “sorry I mean Japanese food”.
Prince William dropped the clanger on a tour of Japan House on London’s Kensington High Street on Thursday, taking in examples of the country’s finest art, design and gastronomy.
On the tour, accompanied by Japanese deputy prime minister Taro Aso, he met husband and wife design team Haruna Yamada and Hirokazu Kabayashi, who met at university.
Admitting Kate, Duchess of Cambridge, is more “arty and creative” than he is he told them they were “just like me and my wife”.
The duke also sipped sake rice wine in a morning toast, and tried some “delicious and amazing” salmon sashimi prepared specially by famed chef Akira Shimizu.
Prince William said: “”My wife and I love sushi. We might have to come down here for lunch when there’s no-one else down.”
He joked: “Just as long as you don’t get people coming in and saying: ‘I’ll have a burger.”‘
William also saw a demonstration of the ancient craft of copper-beating, where objects like kettles are fashioned out of a single sheet of the metal.
Japan House aims to deepen understanding of the East Asian island nation as it prepares to host both the 2019 Rugby World Cup and the 2020 Tokyo Olympic and Paralympic Games.
William said “holding a rugby ball always gets me excited”, and he noted that sport seems to reliably cut across cultures.
Mr Aso thanked William for his work on fighting the illegal wildlife trade in a speech, and said his presence at the opening “promises to enhance the magnetic power of this house”.
The duke said he hopes Japan can use its “expertise and experience” to influence its Asian neighbours to tackle the “abhorrent international crime”.
He also offered condolences over the series of deadly natural disasters which have hit Japan this summer.
William added that he had been “deeply honoured” to visit Japan three years ago where he saw the “wonderful blend of ancient and modern which so characterises your amazing country”.
He finished by unveiling a plaque and leading a traditional kanpai toast, where sake is enjoyed from a wooden cup called a masu.