Britain's Prince William (L), Duke of Cambridge, tries on a samurai costume as Japanese actress Mao Inoue in kimono looks on, during his visit a Taiga historical drama studio set at NHK (Japan Broadcasting Corporation) in Tokyo, February 28, 2015, in this photo released by NHK. [Photo/Agencies]

Pulling rank, it was the British Ambassador, then, who had to don the wig, with his slightly ridiculous-looking photo going semi-viral on Twitter.

But the prince didn't get away scot-free, as he was finally convinced to dress in a costume worn by samurai warlord Toyotomi Hideyoshi, who features on the popular historical NHK drama Taiga. The gaudy costume comprised a garish red and gold tunic, with the finish touch being a gleaming helmet plonked on the Duke's head.

Asked how he felt, the prince replied, "I feel ready for action," and joked regally, "I feel there should be a sword in my hand."

Before playing dress up, the prince enjoyed a traditional dance show from three actresses in the show, accompanied by music from a shamisen.

The female lead of the show, Mao Inoue, presented Prince William with a bouquet of flowers and a hand-made wooden toy, for the prince's son.

At his next engagement at the famed British-built Tsutaya bookstore in Daikanyama, the three-storied sprawling "Forest of Books" being the only of its kind in Japan, Prince William was greeted by throngs of fans as evidence mounts that "William Fever" is definitely catching on, with many of them waving Union Jack flags, and one fan even dressing her pug puppy in an adorable Union Jack doggy sweater, much to the prince's delight.

The bookstore over the next few days is holding a British fair called "Great British Days" and is showcasing art, crafts and innovative products from the United Kingdom, including a collection of official Buckingham Palace accessories, traditional British sweets and condiments, as well as host of British-based books.