MOS Food Services, Inc., the operator of MOS Burger, is launching the “Mazeru VALX Shake – Blueberry Yogurt Flavor” (まぜるVALXシェイク ～ブルーベリーヨーグルト風味～) in collaboration with fitness brand VALX. It will be sold from Thursday, October 1, 2026 through early November at 385 MOS Burger locations in Tokyo, Kanagawa, Chiba and Saitama. The shake is available only in limited quantities and only in this region. To celebrate the launch, a prize campaign offering original goods will also be held.
Background of the Collaboration
The market for protein supplement foods has continued to grow in recent years. Its users now go beyond athletes and people who train regularly to include a broad range of consumers who care about beauty and health. In response to this growing demand, MOS Burger is partnering with VALX. The goal is to offer new value to health-conscious customers, and VALX is a brand widely supported in the fitness and body-making field.
VALX is a fitness brand supervised by Yoshinori Yamamoto, one of Japan’s leading body-making trainers. Built on the concept of “great taste, easy mixing and generous formulation,” it offers high-quality protein and supplements. VALX aims to make “the most delicious protein in Japan,” and it carefully selects ingredients and taste-tests its products again and again. That approach resonated with MOS Burger’s mission of “making people around the world happy through food,” leading to this collaboration.
About the New Shake
The shake combines a sauce containing 13g of VALX protein powder per serving with MOS Burger’s vanilla MOS Shake. Pairing yogurt-flavored protein with blueberry juice creates a refreshing yet satisfying taste.
Product Details
- Product: Mazeru VALX Shake – Blueberry Yogurt Flavor
- Price: ¥610 (M size, tax included)
- Contains: 13g VALX protein powder (per serving); 0.2% triple-concentrated blueberry juice
- Sales period: Thursday, October 1, 2026 – early November (limited quantities; while supplies last)
- Locations: 385 MOS Burger stores in Tokyo, Kanagawa, Chiba and Saitama prefectures
Nutrition Facts (per 330g serving)
- Energy: 387 kcal
- Protein: 12.6g
- Fat: 7.0g
- Carbohydrates: 86.1g
- Salt equivalent: 0.6g
Note that “13g” refers to the amount of protein powder added. According to the nutrition label, each serving contains 12.6g of protein.
Prize Campaign with Exclusive Collab Goods
To celebrate the launch, MOS Burger is also running a prize campaign offering original VALX collaboration goods. As a bonus, every entrant receives voice data recorded by Yoshinori Yamamoto himself.
Campaign Overview
- Entry period: Thursday, October 1, 2026, 7:00 – Wednesday, October 21, 2026, 23:59
- How to enter: Visit the special website listed in the campaign post on MOS Burger’s official X account and upload a purchase receipt for an eligible item. Winners are chosen by lottery.
Eligible Items
- Mazeru VALX Shake – Blueberry Yogurt Flavor
- Nine items made with a soy patty: Soy Hamburger, Soy Cheeseburger, Soy MOS Burger, Soy MOS Cheeseburger, Soy Spicy MOS Burger, Soy Spicy MOS Cheeseburger, Soy MOS Vegetable Burger, Soy Teriyaki Burger, and MOS no Natsumi Soy MOS Vegetable Burger
Prizes
- Yamamoto-sensei Kinni Cushion (1 winner): an arm-shaped cushion made to match the size of Yoshinori Yamamoto’s arm
- VALX × MOS BURGER Yamamoto-sensei Voice Alarm Clock (100 winners): features Yoshinori Yamamoto’s voice
- Voice data recorded by Yoshinori Yamamoto: all entrants
A key point is that you can enter with a receipt for one of the soy-patty burgers, not just the shake. However, entries close on Wednesday, October 21 at 23:59. The shake stays on sale until early November, so be careful not to miss the entry deadline.
About VALX
VALX is a fitness brand that continually pursues “the real thing,” developing cutting-edge products and services with ample quantities and high quality. Under the supervision of Yoshinori Yamamoto, a legend among trainers, it offers supplements, apparel and training gear, and also runs fitness gyms. Its YouTube channel, “VALX Yoshinori Yamamoto Kintore Daigaku” (Muscle Training University), has over 780,000 subscribers, and its total social media following exceeds 1.58 million.
Summary
The Mazeru VALX Shake – Blueberry Yogurt Flavor blends protein from a popular fitness brand with MOS Burger’s signature shake. It is a limited-time offering available only in the Greater Tokyo area. You can enjoy its refreshing blueberry-yogurt taste at MOS Burger locations in Tokyo, Kanagawa, Chiba and Saitama starting Thursday, October 1. Quantities are limited, so go early if you’re interested.
Source: press release by 株式会社モスフードサービス (PR TIMES, in Japanese)