ZOZO Marine Stadium's "Domed Conversion" Reconsideration Initiated at Chiba Lotte's Request, Aiming for Improved Comfort and Economic Benefits

The possibility of "domed conversion" for ZOZO Marine Stadium (formerly Chiba Marine Stadium), home to the Chiba Lotte Marines, which has been debated for some time, will now be seriously reconsidered following a request from the team. Chiba City announced on the 20th that it would proceed with examining the domed conversion as part of the stadium's redevelopment project, based on a request from Mr. Shunsuke Kosaka, Representative Director and President of the Chiba Lotte Marines.

The backdrop to this reconsideration is the increasing severity of weather impacts, such as extreme heat and strong winds and rain, due to recent climate change. On social media, numerous calls for improved comfort for both players and spectators have emerged, with comments like, "It's too hot in summer, all stadiums should be domed" and "No more rainouts, please." A domed stadium would not only reduce the burden on players and allow spectators to enjoy baseball in a comfortable, all-weather environment, but also increase opportunities for concerts and international events, expecting a ripple effect on the regional economy.

On the other hand, a domed conversion entails significant costs, making private investment a prerequisite. The Mayor of Chiba emphasized this point in a press conference, and the Chiba Lotte Marines themselves are expected to make a substantial contribution. Realistic opinions regarding fundraising are also seen on social media, such as, "It'll be tough unless Lotte contributes a good amount," and "The city seems to be softening its stance, saying it wouldn't mind if private entities fund it, but who exactly are these 'private entities'?" Some even express hope for fan support, suggesting, "The realization of a domed stadium depends on how much money can be raised, so there should be crowdfunding for Lotte fans."

Fans have largely welcomed the news with comments like, "Doming is a big step. It looks like it will create a player- and spectator-friendly environment!" and "Absolutely dome it! We must not repeat crosswind and damaging wind baseball!" Specific requests have also been made, such as "We want a retractable dome" and "We want an enclosed type with effective air conditioning."

Chiba City plans to reach a conclusion on this reconsideration of the domed conversion by spring 2026. All eyes are now on whether the "domed conversion" of ZOZO Marine, a long-standing issue, will come to fruition through the enthusiasm of the team, private sector, and fans.

The context

ZOZO Marine Stadium (formerly Chiba Marine Stadium) is an open-air baseball stadium located in Chiba City, Japan, and is the home ground for the Chiba Lotte Marines, a professional baseball team in Nippon Professional Baseball (NPB). Open-air stadiums in Japan often face significant challenges due to the country's severe summer heat and humidity, as well as the rainy season and occasional typhoons. These weather conditions frequently lead to discomfort for players and spectators, and can result in game cancellations or postponements. The idea of converting such stadiums into domed facilities is a recurring topic of discussion across Japan, driven by desires for improved comfort, increased versatility for hosting various events year-round, and potential economic benefits for the local region.