Matsuya's official X account teases a "mystery cup" — it turns out to be Soy Milk Pudding

Around noon on July 16, Matsuya’s official X account revealed what was inside the container it had deliberately left in the frame of a tasting report two days earlier, the “mystery cup.” The post said, “The mystery cup is Soy Milk Pudding,” and added that it is on sale at all stores except those in Okinawa.

A “mystery cup” revealed two days later

It began with a post on the night of July 14. Matsuya’s official account shared a photo of the Twice-cooked Pork Set Meal, which went on sale that day, and ended the caption with “Hm, what’s that mystery cup in the back…?”, deliberately leaving the container at the back of the table unexplained. About 41 hours later, in the 1 p.m. hour on July 16, the account quoted that post and answered, “The mystery cup is Soy Milk Pudding.” The hint and the reveal were split across two posts to build the tease.

Both the Twice-cooked Pork Set Meal and the Soy Milk Pudding are new items that went on sale together on July 14. Their status differs, however. On Matsuya’s official website menu, the Twice-cooked Pork Set Meal is listed as a limited-time menu item, while the Soy Milk Pudding is listed as one of the side dishes under the regular category rather than the limited-time category.

A 180 yen side dish with kinako and kuromitsu

The published photo shows clearly what the Soy Milk Pudding looks like. A smooth white pudding in a cup is generously dusted with kinako (roasted soybean flour) and drizzled with kuromitsu (brown sugar syrup), giving it the look of a Japanese-style dessert. Even the spoonful lifted from the cup shows the pudding, kinako and kuromitsu layered together. In the lower right of the photo are Matsuya’s official mascots, Macky and Yakky, giving a thumbs-up and a smile to promote the new sweet.

The lid of the container carries the English words “SOY MILK PUDDING” and the Matsuya logo, along with the copy “A privilege for five minutes after your meal” and “Melting, gentle sweetness.”

The price is 180 yen, in the same range as side dishes such as the Sausage and Egg. It is positioned as a sweet you can easily add to finish a meal.

From announcement to sale to reveal

Both the Soy Milk Pudding and the Twice-cooked Pork Set Meal were announced in advance in an official notice dated July 9, and they actually appeared in stores and on the menu five days later, on July 14. From the announcement, through the sale, to the tasting-photo tease and now the reveal, the official account has kept the topic going in stages.

Note that a dish with the same name, written in katakana (“豆乳プリン”), was once tried at limited stores. It has already been delisted and is a different product from the Soy Milk Pudding (written in hiragana, “豆乳ぷりん”) now being rolled out nationwide as a regular item.