Perhaps even more surprising is that this species of grape has consistently broken auction price records since coming onto the seasonal auction market in 2008.

Like other kinds of fresh produce and seafood in Japan, Ruby Roman grapes from the very first yield of the season are sold at the first seasonal auction called hatsuzeri (初競り). These first grapes are considered to bring prestige and good luck, therefore often fetching much higher prices than what is normally sold in stores. In 2008, the highest-priced first grapes of the season sold for 100,000 yen. That price quintupled in 2011 to 500,000 yen for the most expensive bunch. Last year, it doubled again, to 1 million yen.

According to the Wall Street Journal, retail prices start at 25,000 yen a bunch, depending on the quality.

Ruby Roman grapes have been grown in Japan’s northwestern Ishikawa prefecture under a government program since 1994. To qualify as Ruby Roman grapes, each grape must contain at least 18% sugar content, weigh at least 20 grams and have low acidity, according to the Ruby Roman grapes cooperative. There are also different classes of Ruby Roman grapes, with the “special class” required to weigh about 600 grams a bunch, and the “premium class” weighing at least 30 grams per grape, or 700 grams a bunch. Only 6 grape bunches qualified as premium in 2010. None made the cut in 2011.

In the past, the highest grape bidders have included head chefs from hotels, restaurants, a high-end pastry shop and a wedding operator.

📬 Sign up for the Daily Brief

Our free, fast, and fun briefing on the global economy, delivered every weekday morning.