A triple collaboration campaign titled "Eat, Learn, and Support Your Faves! A Spring Journey Through Kappa Sushi with Ireisu!" has launched, bringing together VOISING's 2.5D idol group Ireisu (Irregular Dice), the Colowide Group's rotating sushi chain Kappa Sushi, and the game-based English learning app Risdom. The campaign runs from March 12 through April 15, 2026 (Wednesday) at Kappa Sushi locations nationwide (excluding some branches under renovation).
For more details, visit the official campaign page: https://www.kappasushi.jp/cp/ireisu-risdom
Special Collaboration Menu Chosen by the Members Themselves
The collaboration menu was assembled with input from Ireisu members, who selected their personal favorite toppings. Two sets are available:
The Adult Group Set features 10 pieces chosen by the adult members (Naiko, If, and Yusuke), including medium fatty tuna, tuna, generously cut salmon, and live-filleted yellowtail, paired with a "Spring-Color Chawanmushi" (savory egg custard).
The Kids Group Set centers on favorites picked by the younger members (Riura, -hotoke-, and Hatsuto), rounded out with popular sushi items, and is topped off with a colorful "Spring-Color Pancake" in hues inspired by each member's image color.
Both sets come with an original A5 notebook featuring newly drawn uniform illustrations, stickers, and an "Ireisu Sheet" — a tabletop display designed to give diners the feeling of sharing a meal with the members.
Note: Items are available in limited quantities and may sell out. Menu contents may vary due to seasonal availability. Please check the official website and contact individual stores for details.
In-Store Announcements, Original Music, and Animated MV
Kappa Sushi locations are broadcasting newly recorded voice announcements by Ireisu members once every hour. An original arrangement of the Kappa Sushi theme — "Kappa Sushi no Theme: Ireisu Arrange Ver." — also plays in stores.
Starting March 12, a specially produced animated music video featuring new illustrations plays in-store on order touchscreen panels (audio-free on panel screens). The same MV is also available on Ireisu's official YouTube channel.
Additionally, 20 specially decorated locations across Japan are running an expanded in-store experience, with large photo panels and table stickers using newly drawn illustrations. Participating stores can be found in Tokyo, Kanagawa, Saitama, Chiba, Nara, Miyagi, Iwate, Osaka, Aichi, Hiroshima, and Fukuoka. See the campaign website for a full list of participating stores.
Campaign site: https://www.kappasushi.jp/cp/ireisu-risdom
Collaboration Event Also Live in the Risdom App
The Risdom app has also switched to a collaboration mode from March 12. Ireisu members appear in collaboration outfits, and the special track is playable as a rhythm game. Newly drawn visuals are also included, and Risdom's characters Alice and Ridel make appearances in Kappa Sushi uniforms, with mascots Kaa-kun and Paa-ko-chan joining in.
Customers who order a collaboration set can receive special in-app items for Risdom through a linked campaign running simultaneously.
Campaign Overview
- Period: March 12, 2026 (Thursday) – April 15, 2026 (Wednesday) (subject to change)
- Locations: All Kappa Sushi locations nationwide (excluding some under renovation)
- Campaign site: https://www.kappasushi.jp/cp/ireisu-risdom
Collaboration menu items are available in limited quantities and will end when sold out. Prices and stock may vary by location.
About Ireisu (Irregular Dice)
Ireisu (Irregular Dice) is a six-member 2.5D idol group under VOISING Inc., formed in October 2020. The group is active across singing cover videos, original songs, variety content, and live streaming. Beyond the internet, they have held live concerts and collaboration events, rapidly growing in popularity. In 2023, they completed a hall tour across six cities. In February 2024, they achieved a long-promised milestone with a live show at Nippon Budokan. In November and December 2024, they held their first-ever dome performances at Belluna Dome over two days. In the summer of 2025, they completed their first nationwide arena tour as Ireisu, drawing a total audience of 90,000.
Left column (top to bottom): -hotoke-, Hatsuto, Riura / Right column (top to bottom): If, Yusuke, Naiko
