MOS Burger Introduces New Plant-Based Burger Made Without Animal Ingredients: 'Avocado Basil Burger with Rice Flour Bun'

MOS Food Services, Inc. (President: Eisuke Nakamura, Headquarters: Shinagawa-ku, Tokyo), operator of MOS Burger, has announced that starting Wednesday, May 20, 2026, it will launch the new "Avocado Basil Burger with Rice Flour Bun" at MOS Burger stores nationwide (excluding select locations). This burger uses vegetables and grains as its main ingredients, completely avoiding animal-derived products in its primary materials. Concurrently, the entire existing "Soy Patty" series lineup will be renewed. ■ Development Background Guided by the desire for "customers with various circumstances and preferences to enjoy dining together with peace of mind," the company has consistently developed forward-looking menus. This includes the launch of "MOS Natsumi" (where ingredients are wrapped in lettuce instead of buns) in 2004, "Low Allergen Menus" in 2009, and the "Soy Patty" featuring soy-derived plant protein instead of meat in 2015. In recent years, amid diversifying food cultures and values and the spread of the "food diversity" concept, the "Green Burger," introduced in 2020 with vegetables and grains as main ingredients and no animal products, received significant acclaim. The newly launched "Avocado Basil Burger with Rice Flour Bun" maintains the concept of excluding animal ingredients in its main components, utilizing a newly developed bun made with a blend of wheat and rice flour, paired with rich and creamy avocado. The company focused on deliciousness to appeal not only to those with dietary restrictions but also to a wide range of customers, including the health-conscious. Alongside this, the "Soy Patty" will be renewed for the first time in 6 years. <3 Key Features> 1. New Soy Patty: Improved the dryness typical of soy-derived plant proteins, achieving an aroma and texture closer to real meat. For this renewal, two types of plant proteins (granular and powdered) derived from soy and wheat were used to replicate a meaty flavor and texture. By incorporating onions, the patty retains a plump and soft texture while adding the right amount of umami and sweetness. Additionally, an iron-plate baking process was added during factory production to bring out a savory aroma, and the patty was made thicker than the previous version for a more satisfying bite. 2. Rice Flour Bun: Deliciously chewy texture The newly developed bun contains an optimal amount of rice flour mixed into wheat flour. The addition of rice flour allows for a freshly baked chewy texture, while the balance of rice and wheat flours was carefully adjusted so it does not become too hard when taken out. 3. Plant-Based Tartar Sauce (Domestic Basil): Refreshing tartar sauce using plant-based mayo This tartar sauce combines a plant-based mayo base with domestic basil and dried onions. By adding miso as a secret ingredient, it achieves a sauce that is refreshing yet rich in flavor. It is served separately, allowing customers to adjust the amount to their liking. ● "Avocado Basil Burger with Rice Flour Bun" (620 yen) A burger made primarily of vegetables and grains without using animal ingredients in its main materials. The renewed new Soy Patty is topped with diced avocado, green leaf lettuce, sliced tomatoes, and sliced onions, all sandwiched between a rice flour bun. By adding the separately provided "Plant-Based Tartar Sauce (Domestic Basil)" to your liking, you can enjoy a refreshing flavor change. The Soy Patty, which has evolved into a meatier aroma and texture, combined with large cuts of avocado, delivers an incredibly satisfying meal. It is a product that pursues not only careful ingredient selection but also "deliciousness," aiming to satisfy everyone. * Served with a separate sauce packet. Please pour it little by little to your liking. * Some sub-ingredients contain materials other than vegetables and grains. * Contains onion, which is one of the five pungent roots. * This is not a low-allergen menu item. * For details on cross-contamination, please refer to the allergy information on the official website. * This product is a Plant-Based Food Certified Product. It is the company's second certified product following the "Green Burger ". This burger is made primarily of vegetables and grains, without using animal ingredients in its main materials. The food manufacturing factories and stores produce and handle products containing animal ingredients. ■ Product Name & Price: "Avocado Basil Burger with Rice Flour Bun" (620 yen) ■ Sales Start Date: Wednesday, May 20, 2026