Starting March 18, 2026 (Wednesday), Mos Burger locations across Japan (excluding some stores) will kick off their first-ever collaboration with Coji-Coji, the beloved fantasy manga series by Sakura Momoko. The collaboration features exclusive character giveaways available with kids' meal sets, as well as a brand-new menu addition.
Coji-Coji Collaboration Giveaways
Coji-Coji is a work set in the whimsical Fairy Tale Land, created by Sakura Momoko, the author of Chibi Maruko-chan. Despite being a gag series, its characters offer layers of depth, making it enjoyable for both children and adults alike. For this collaboration, specially drawn illustrations depicting Coji-Coji and friends enjoying burgers and drinks appear on giveaway items and tray mats available during dine-in visits (tray mats are not available at some stores including Mos Burger & Cafe, and supplies are limited).
There are four types of giveaway items to choose from:
Coji-Coji Stick-and-Color Sticker Sheet – A coloring sheet where kids can add color using transparent stickers (comes as a 2-sheet set).
Coji-Coji Sticker Tin Case – A tin case filled with stickers featuring the collaboration's original illustrations.
Coji-Coji Chatting Magnet – A fun magnet designed to stick on the fridge or other surfaces.
Coji-Coji Mos Chicken Sticky Notes – Sticky notes featuring a design of Coji-Coji imitating Mos Chicken.
One giveaway item can be chosen with the purchase of a qualifying Mos Wai Wai Set or a low-allergen menu set. Note that Coji-Coji giveaway items are not available for individual purchase.
Giveaway Period: March 18, 2026 (Wednesday) to late May 2026 (while supplies last)
Available at: Mos Burger locations nationwide (excluding some stores)
New Product: Wai Wai Teriyaki Burger Set
A new addition is joining the Mos Wai Wai Set lineup: the Wai Wai Teriyaki Burger Set (¥610). The Mos Wai Wai Set is a kids' meal series that avoids mustard and raw onions, making the flavors gentler for younger diners. It combines a burger or chicken nuggets with French fries (S size), a drink, and an original giveaway item.
The new Wai Wai Teriyaki Burger features a teriyaki-sauced patty with shredded lettuce and a half-calorie mayonnaise-type sauce. The ingredients are the same as the regular Teriyaki Burger, but the lettuce is shredded and the amounts of sauce are reduced to make it easier for kids to eat. The Wai Wai Teriyaki Burger is only available as part of the set, not individually.
Also launching at the same time is the Apple Juice (¥100), a refreshing juice made to bring out the natural flavor of apples.
Sales Period: From March 18, 2026 (Wednesday) onward — a permanent addition to the menu
Available at: Mos Burger locations nationwide (excluding some stores)
Collaboration Giveaway Set Menu Options
Mos Wai Wai Set (¥540–¥660)
Includes a choice of burger or nuggets (Wai Wai Mos Cheeseburger, Wai Wai Burger, Wai Wai Cheeseburger, Wai Wai Teriyaki Burger, or Wai Wai Nuggets) + French Fries S + Drink (Apple Juice, Cold Drink S Orange Blend 100 S, or Mos Shake S for an additional ¥50) + Giveaway item. The Mos Wai Wai Set is not a low-allergen menu.
Low-Allergen Menu with Drink and Giveaway Set (¥590)
The low-allergen menu avoids the use of the eight major allergens (eggs, dairy, wheat, shrimp, crab, buckwheat, peanuts, and walnuts) as ingredients. The set includes a choice of low-allergen menu item (Pork Sand <Rice Flour> or Pork Roll <Rice Flour>) + Drink + Giveaway item. Drinks may contain allergens; please check allergen information for details.
About Coji-Coji
Coji-Coji is a fantasy/nonsense gag series by Sakura Momoko, the creator of Chibi Maruko-chan. Set in a fairy tale land where character residents have a mission to entertain humans, the story follows the everyday life of Coji-Coji — a space creature of unknown age and gender — and a peculiar cast of companions. The manga ran from 1994 to 1997 and continues to be serialized irregularly in Ribon. An anime adaptation aired from 1997 with a long run of 101 episodes, featuring many original stories with social commentary woven in.
- Website: https://cojicoji.site/
- X (formerly Twitter): https://x.com/cojicoji_tweet
- Instagram: https://www.instagram.com/cojicoji.official/
- TikTok: @cojicoji.official (https://www.tiktok.com/@cojicoji.official)
- Facebook: https://www.facebook.com/cojicoji.official/
- YouTube: https://www.youtube.com/c/cojicojichannel
All prices listed are tax-inclusive.
