Mos Burger has launched new autumn-themed sweet potato treats in Japan, available from August 28, 2026. The menu features the “Otsuatsu Osatsu Ball – Purple Sweet Potato” and the “Mazeru Shake – Anno Sweet Potato.”
For those exploring seasonal dessert options across Japan, Mos Burger offers these sweet potato specialties nationwide at most of its stores, running through early November.
The “Otsuatsu Osatsu Ball – Purple Sweet Potato” comes in 3-piece for ¥290 and 5-piece for ¥470. The “Mazeru Shake – Anno Sweet Potato” is available in small size for ¥410 and medium size for ¥470. Customers can also add the medium shake as a set drink for an additional ¥130.
About Mos Burger’s Autumn Sweet Potato Menu
The “Otsuatsu Osatsu Ball – Purple Sweet Potato” is inspired by Taiwanese QQ balls, featuring a chewy dough infused with domestically sourced Beniharuka sweet potato powder, shaped like a full moon. Inside, it contains a moist and mildly sweet filling made from Japanese purple sweet potatoes. The balls maintain their chewy texture even when cooled, and caution is advised as they are served hot.
The “Mazeru Shake – Anno Sweet Potato” combines a rich sauce made from roasted Anno sweet potatoes grown on Tanegashima Island, Kagoshima, with a classic vanilla shake. The sauce is hand-peeled and mashed to preserve its naturally high sugar content, enhanced with brown sugar and Patagonia salt for depth. The drink’s golden color evokes the image of a full moon, fitting the autumn theme.
Highlights
- “Otsuatsu Osatsu Ball – Purple Sweet Potato” available in 3-piece (¥290) and 5-piece (¥470) options.
- “Mazeru Shake – Anno Sweet Potato” offered in small (¥410) and medium (¥470) sizes, with a set drink option for an extra ¥130.
- Seasonal menu runs from August 28 to early November 2026 at most Mos Burger locations nationwide.
- Uses domestically sourced purple sweet potatoes and Kagoshima-grown Anno sweet potatoes.
- Menu inspired by the full moon and the traditional Japanese autumn festival Tsukimi.
Menu & Event Details
| Item | Details |
|---|---|
| Name | Mos Burger Autumn Sweet Potato Menu |
| Menu / items | “Otsuatsu Osatsu Ball – Purple Sweet Potato” (3 pieces ¥290, 5 pieces ¥470); “Mazeru Shake – Anno Sweet Potato” (Small ¥410, Medium ¥470, Set drink +¥130) |
| Period | August 28, 2026 – Early November 2026 |
| Location | Nationwide Mos Burger stores (excluding some locations), Japan |
| Price | ¥290, ¥470, ¥410, ¥470, plus ¥130 for set drink (all tax included) |
Before you buy
- When can I buy Mos Burger’s autumn sweet potato menu?
- From August 28, 2026, until early November 2026 at most Mos Burger stores across Japan.
