The Nippon Ham Fighters announced the sale of the naming rights for their new stadium in Kita Hiroshima, Hokkaido, on Wednesday, saying the value of the deal is believed to be the highest in the history of sports in Japan, exceeding the 470 million yen ($4.3 million) a year paid by Nissan for the rights to Yokohama International Stadium — the home of the J-League’s Yokohama F Marinos soccer club.

Here’s the Fighters English page.

The natural grass field with a retractable roof is expected to open for business in 2023 and will be known as ES CON Field Hokkaido. The new naming rights holder is real estate developer ES-CON Japan, a subsidiary of the Chubu Electric Power Group that will be involved in the development of the surrounding property — known as Hokkaido Ballpark F Village.

The development is located near Kita Hiroshima Station about 8 kilometers east of the Fighters’ current home, Sapporo Dome.

When it is built, it will give all six Pacific League teams complete operating rights over their ballpark. Orix, SoftBank, and Seibu are the majority owners of their stadiums, while Rakuten and Lotte hold operating licenses. Only three of the six Central League clubs own the operating rights to their stadium.

The Fighters relocated to Sapporo in 2004, where they have dramatically increased the size of their fan base and their sponsorship revenues. In addition to the new ballpark, the team has also negotiated a major upgrade of its spring training base in Nago, Okinawa Prefecture.