Tokyo DisneySea, the popular marine-based amusement park next to Disneyland, marked its 15th anniversary Sunday with Mickey Mouse and the other Disney characters welcoming visitors with a dance performance.

Toshio Kagami, chairman of Oriental Land Co., operator of the Tokyo Disney Resort complex in Urayasu, Chiba Prefecture, vowed during a commemorative ceremony to continue developing DisneySea into a "unique theme park which can only be found here."

Tokyo Disneyland opened in April 1983. Together, Tokyo DisneySea and Disneyland had drawn 660 million visitors by the end of March.

The ceremony's highlight was a dance number performed by Mickey Mouse and other Disney characters, including Minnie Mouse and Donald Duck, at the park's harbor area.

The park opened on Sept. 4, 2001, featuring attractions related to the sea and in the hope of bringing in more adults.

Tokyo DisneySea began commemorative events for its 15th anniversary, titled "The Year of Wishes," in April. The anniversary ceremony was initially set for April 15 but was rescheduled following a series of powerful earthquakes that hit Kumamoto Prefecture and other parts of southwestern Japan.