You need to go to the Kesei Bus station which is located immediately behind the Tokyo metro station. From there you can buy a combined bus/park ticket. The place is almost an hour and a half away but totally worth it. the bus will take you to Kamogawa Bus/railway station where you will board the FREE shuttle bus that runs every 20 mins to the park. The bus/park entrance was 2300yen.
the park itself is well laid out, well looked after, and well organised. You will spend a whole day here and the animal shows are staggered so you can see everything. The main highlights were the Beluga whales and the Orcas.
Expensive as per Japan and expensive as per any zoo/water park anywhere in the world. If you want to eat here you can there is a wide selection, I would however bring my own food.
Get a poncho or sit on the back row YOU WILL GET WET.... for me that was half the fun.More