GMO Internet Group to Sponsor 'GMO Water Splash Festival 2026 in Keyaki Hiroba' as Top Sponsor

GMO Internet Group Co., Ltd. (Representative Director and Group CEO: Masatoshi Kumagai; hereinafter 'GMO Internet Group') will serve as the top sponsor for the summer participatory event 'GMO Water Splash Festival 2026 in Keyaki Hiroba – Keyaki Water Splash,' hosted by Saitama Arena Co., Ltd. The event will take place over three days from Saturday, July 18 to Monday, July 20, 2026 (a national holiday), at Keyaki Hiroba in Saitama City's Saitama Shintoshin district.

GMO Internet Group is committed to enhancing vibrancy in the area surrounding 'GMO Arena Saitama,' including Keyaki Hiroba, delivering smiles and感动 to local communities.

[Background of Sponsorship]

GMO Internet Group has been actively fostering community engagement and urban vitality centered around GMO Arena Saitama.

On March 30, 2026, GMO Internet Group signed a Value-Up Naming Rights Partnership Agreement with Saitama Prefecture and Saitama Arena Co., Ltd., officially renaming the 'Saitama Super Arena' to 'GMO Arena Saitama' effective April 1, 2026 (Note 1). GMO Internet Group views this naming rights initiative not merely as a branding exercise, but as a strategic effort to merge top-tier technology with hospitality, aiming to evolve the arena and contribute to the local community. This sponsorship is part of that broader initiative, contributing to area-wide activation.

(Note 1) Official Announcement: 'Saitama Super Arena' Renamed to 'GMO Arena Saitama' – https://group.gmo/news/article/9963/

[Event Overview]

This event is a participatory festival inspired by Southeast Asian 'water-splashing festivals' (Songkran), where attendees splash water on each other to celebrate bountiful harvests and good health. Centered at the Keyaki Hiroba Sunken Plaza, it welcomes participants of all ages to get soaked and have fun. In addition to water-splashing sessions, the festival features a wide variety of food stalls, workshops, and stage performances, offering a full summer experience in Saitama Shintoshin from day into night.

Event Name

GMO Water Splash Festival 2026 in Keyaki Hiroba – Keyaki Water Splash

Dates and Times

July 18 (Sat) – July 20 (Mon, Holiday), 2026

11:00 – 21:00 (until 20:00 on the final day)

Venue

Keyaki Hiroba, Saitama Shintoshin

(Sakura-ku, Saitama City / 3-minute walk from JR Saitama-Shintoshin Station)

Admission

Free

Activities

- Water Splash Sessions (3 times daily: 11:00–12:00, 13:00–14:00, 15:00–16:00)

- Food and beverage stalls, workshops, live stage performances

- Water Splash DJ Time, and concurrent exhibition 'TOMUSHI's Kabukuwa is Amazing!!'

Organizer

Saitama Arena Co., Ltd.

Top Sponsor

GMO Internet Group

Website

https://www.saitama-arena.co.jp/event/mizukake26/

[About 'GMO Arena Saitama']

'GMO Arena Saitama' is the new official name assigned to the former 'Saitama Super Arena' starting April 1, 2026, under the Value-Up Naming Rights Partnership Agreement signed on March 30, 2026, between GMO Internet Group, Saitama Prefecture, and Saitama Arena Co., Ltd.

GMO Internet Group aims to create a 'Smart Arena' by integrating top-tier technology with hospitality. Initiatives include enhancing cashless payment systems in concession stands, upgrading high-speed internet and Wi-Fi infrastructure, exploring AI and robotics applications, and strengthening disaster preparedness and community contribution functions, all aimed at increasing facility value while addressing regional challenges.

Facility Name

GMO Arena Saitama

Location

8 Shintoshin, Sakura-ku, Saitama City

Opened

September 2000

Capacity

Approx. 37,000 (stadium mode)

Annual Visitors

Approx. 2.87 million (2024 fiscal year)

Total Visitors

Over 60 million (since opening in 2000)

Main Uses

Concerts, sports events, exhibitions, ceremonies, etc.

Closure Period

Expected from January 2026 to March 2027

[About GMO Internet Group]

GMO Internet Group is a comprehensive internet conglomerate with core businesses in internet infrastructure—including domains and hosting services—as well as internet security, advertising and media, internet finance, and cryptocurrency.

Positioning itself as the 'No.1 Group Creating the Future with AI & Robotics,' the company leverages generative AI across all group partners to achieve: ① time and cost savings, ② improved quality of existing services, and ③ new service offerings in the AI industry. Furthermore, by widely providing robotics as physical AI, it aims to solve societal challenges.

[Corporate Information – GMO Internet Group Co., Ltd.] (URL: https://group.gmo/)

Company Name: GMO Internet Group Co., Ltd. (Tokyo Stock Exchange Prime Market, Stock Code: 9449)

Headquarters: Cerulean Tower, 26-1 Sakuragaoka-cho, Shibuya-ku, Tokyo

Representative: Representative Director and Group CEO, Masatoshi Kumagai

Business: Holding company (group management functions)

Group Business Segments:

- Internet Infrastructure

- Internet Security

- Internet Advertising & Media

- Internet Finance

- Cryptocurrency

Capital: 5 billion JPY

Copyright (C) 2026 GMO Internet Group, Inc. All Rights Reserved.