Among the hundreds of gilded and finely painted cups and saucers of "Demitasse Cosmos: Glitter of Jewelry" at the Mitsui Memorial Museum is a modest set that may be easily overlooked. Emerald green in glaze, with a simple black handle and rim, it's a far cry from its neighbors that impress with gold trimming, enamel-jeweling and all manner of colorful and ornamental designs.

Yet this unassuming 1924 Royal Doulton coffee cup is one of the most important, at least from a sentimental point of view. It was this demitasse that inspired an ordinary couple — Yasuhiro and Tomiko Suzuki — to begin a collection that would, over a period of more than 45 years, amass into a vast eye-catching array of creative craftsmanship.

The little green cup is also a personal memento, having once belonged to Yasuhiro's grandfather — a cultured man who bought and used it in England during the 1920s.