Photo/Illutration A concept image of the Osaka-Kansai Expo's water show "Under the Midnight Rainbow" (Provided by Suntory Holdings Ltd. and Daikin Industries Ltd.)

OSAKA--Construction on Yumeshima has begun for the 2025 Osaka-Kansai Expo's aqua show "Under the Midnight Rainbow," which is expected to be one of the largest water shows ever staged at a world expo.

Sponsors Suntory Holdings Ltd. and Daikin Industries Ltd. kicked off the construction on the artificial island with a traditional groundbreaking ceremony on July 8.

They also unveiled plans behind the twice-nightly show that will run from April 13 to Oct. 13. 

The 20-minute spectacle with music, projections and lasers is about a festival celebrating the appearance of rainbow in the middle of the night and Ao, a child who stumbles upon it.    

Some 300 fountains will be built on the Water Plaza stage, which stretches 200 by 60 meters, while the arena will seat a maximum of 2,500 spectators.

However, the centerpiece of the ambitious production is a planned 18-meter-long water cascade—an artificial waterfall that will double as a projection screen.

The show is free for expo visitors. Advance reservations are also possible with 1,000 reserved seats. The companies will start accepting reservations this autumn.