Location: 1 hour 30mins drive from Tokyo, and registration on the day.
Swim: In the river, not too bad but shame they can't use the ocean and if rough then change to river. Long swim to bike transition.
Bike: Good bike course. 20k out along toll road and then 20k back. Flat and fast.
Run: Along the beach. Flat run, but about 11k, you'd think they could get that right!
After party: Some good Japanese stalls selling food and beers. If the weather is good then even better.