Burger King®'s Hit Product 'Mushroom' Debuts with Cheese Buns! The 'Mushroom Ugly Burger®' Featuring Four Types of Mushrooms Sandwiched in a Carefully Crafted 'Four-Cheese Craft Bun' is Now on Sale for a Limited Time!

BK Japan Co., Ltd. (Headquarters: Chiyoda-ku, Tokyo; Representative Director and President: Kazuhiro Nomura) will launch the 'Mushroom Ugly Burger®' for a limited time starting Friday, May 8, 2026. This burger features four types of mushrooms and a flame-grilled 100% beef patty, sandwiched in a meticulously handcrafted 'four-cheese craft bun' and finished with a mellow sour cream and onion paste umami with a hint of three herbs in a 'special sour cream onion sauce'. As the latest in Burger King®'s highly successful 'Mushroom' series of limited-time products, the 'Mushroom Ugly Burger®' makes its limited-time debut. It features a flame-grilled 100% beef patty, sandwiched in the meticulously handcrafted 'four-cheese craft bun' used in the popular 'Ugly Burger' series, and finished with a 'special sour cream onion sauce'. The 'Mushroom Ugly Burger®' uses a generous amount of four types of cheese in its meticulously handcrafted 'four-cheese craft bun'. It sandwiches Burger King®'s proud flame-grilled 100% beef patty, four types of mushrooms including two types of roasted mushrooms, king oyster mushrooms, and shimeji mushrooms, along with fresh lettuce, tomato, and onion. It is finished with a mellow and rich 'special sour cream onion sauce' made with sour cream, onion paste, and three herbs (oregano, thyme, and celery seeds), and mayonnaise sauce. The texture of the four types of mushrooms and the craft bun is addictive, making it a hearty and authentic burger. The 'four-cheese craft bun' used in the 'Mushroom Ugly Burger®' is made by evenly applying refreshing Gouda cheese, mild Egmont cheese, and subtly sweet Mozzarella cheese to the dough before fermentation. Then, Cheddar cheese is manually layered again and baked. Due to the extensive manual work, only about one-third the quantity of regular buns can be produced. We invite all Burger King® 'Mushroom' series fans and mushroom lovers to enjoy the latest in the highly successful 'Mushroom' series, the 'Mushroom Ugly Burger®', on this occasion. Meticulously handcrafted with a generous amount of four types of cheese, The specially crafted 'Four-Cheese Craft Bun' To deliver a more delicious burger, we developed the specially crafted 'four-cheese craft bun' through repeated improvements over a long period. Refreshing Gouda cheese, mild Egmont cheese, and subtly sweet Mozzarella cheese are evenly applied to the dough before fermentation, and then Cheddar cheese is manually layered again and baked. Due to the extensive manual work involved in the 'four-cheese craft bun', only about one-third the quantity of regular buns can be produced. Product Overview Product Name: Mushroom Ugly Burger® Release Date: Friday, May 8, 2026 - Sunday, May 17, 2026 Price: Single item 1,090 yen, Set 1,390 yen The regular menu items 'Cheese Ugly Burger®', 'Double Cheese Ugly Burger®', and 'Triple Cheese Ugly Burger®' are also currently on sale. Product Name: Cheese Ugly Burger® Price: Single item 940 yen, Set 1,240 yen Product Name: Double Cheese Ugly Burger® Price: Single item 1,340 yen, Set 1,640 yen Product Name: Triple Cheese Ugly Burger® Price: Single item 1,740 yen, Set 2,040 yen *Sets include French fries (S) and a drink (M). *Regarding the 'Mushroom Ugly Burger®', it will be sold after 10:30 AM at stores offering morning menus. *Regarding the 'Mushroom Ugly Burger®', as it is a limited quantity product, sales will end once sold out. *Not available at some stores. *Sales hours may vary by store. *Sales may be temporarily suspended depending on store conditions. *All prices include tax. *Product design and prices may change without prior notice. *Images are for illustration purposes only. *The following stores do not sell the 'Mushroom Ugly Burger®', 'Cheese Ugly Burger®', 'Double Cheese Ugly Burger®', or 'Triple Cheese Ugly Burger®'. Please be aware. Burger King® Tokyo Racecourse Store (1-1 Hiyoshicho, Fuchu City, Tokyo, Fuji View Stand 2F Food Court) Burger King® Kyoto Racecourse Store (32 Yoshimawataribashimacho, Fushimi-ku, Kyoto City, Kyoto Prefecture, Kyo