The Nirvana Statue represent the death of Buddha when hewas 80 years old. This Buddha is Gandhara style and one of the biggest Nirvana Statue in eastern Asia.
How to worship
First put 5 incense sticks in front of Buddha. 3 of them are for buddhist teaching, one for your ancestor, the last one is for your wish.
Next, take off your shoes and put your hands together and walk around the Buddha 3 times. The path is designed as spiral way, so after 3 time circling around, you will reach at feet of the Buddha.
Put your hands and head on his feet then pray your wish. This is the highly respected way of worship in India, and this is the only spot you can do it in Japan.
This has a great benefit for your lower body especially feet.