Beautiful, Family-Friendly Beaches in Japan

Being from Hawaii, I am pretty strict when it comes to beaches but I must admit that relaxing at a beach "Japanese Style" is pretty great. It has much less to do with the water actually. In Hawaii, I usually spend the entire day in the ocean catching waves and watching the shore from the water. In Japan, I spend the day, cool and comfortable with a sweet drink in my hand under the kind shelter of a Umi-no-Ie or "Ocean House". These usually open up at most of the popular beaches near Tokyo and can cost around 2000 or 2500 yen for the day. They are wooden structures with fresh water showers, tatami mat spaces with low tables for shaded lounging and simple terrace chairs for people and ocean watching. They will have boogie boards and inner tubes on hand to rent and the staff are always so friendly, outgoing and tanned like you wouldnt believe. It is kind of like hanging out inside a lifeguard's station at the beach. This is a great way to stay out of the glaring sun, have a little food and drink (charged separately) and not have to worry about all the sand blowing in your face of overexposure to the sun. This is the area in Katase Enoshima I particularly like.
http://www.shonan1.com/modules/shonan_map/index.php?lid=27&cid=30
(This is not in English but if you scroll down the page you can see some photos)

Dont forget to head out for an evening hot bath at the Enoshima Island Spa once you are finished at the beach. The hot spring water will finish up all the cleansing your skin can enjoy for the day :)
http://www.enospa.jp/medical_eng/guide/index.html