This beach is in Chiba near Tokyo. It is around one and a half hours from Tokyo by a car.
It is possible to swim from Mid-July to Mid-August.
There are UMINOIE (beach cabins) where you can eat curry and noodles, change your clothes, take a shower. There are car parks where cost about NZ$15.
There is the long sandy beach of 66 kilometers and many swimming spots. You can experience JIBIKIAMI which is the way of catching fishes with a net. If wind blows, you will be able to watch a wind-wrought pattern on the sands because the sand is light.
I have been there three times. This beach is so big that you can play beach volleyball and beach flags with your many friends. You can also enjoy marine sports like banana boats, surfboarding, snorkeling, and so on. If you want to go there with your boyfriend or girlfriend, you can enjoy wading in the water while talking together. I strongly recommend you go there!
I have been there when I was child, but I can remember its beatiful seascape clearly. You can enjoy swimming, surfing... lot of sports! And sardines are well-known there, so you can eat them.