The meet was held at the Tatsumi swimming centre, which is only a five-minute walk from the new Olympic aquatic centre under construction. It should be completed early in 2020.
Certainly Ledecky won't drop the 1500m. Her time of 15m 38.97s was the 10th fastest in history. She now owns nine of the top 10 times in that event - and the world record.
"It's something that makes training really challenging and exciting for me to compete in the shorter races," she said. "So I have no plans of dropping anything. Plans could change but I think I still have a lot in me."
As a trial for Tokyo, Ledecky is likely to swim all four next year in the world championships in South Korea.
"I think I know how to manage my races and manage my energy,'' Ledecky said.
The United States won 18 gold medals at the meet, with Australia claiming eight and Japan six.
- AP