These spiders are common in Japan, they are Nephila Clavatas, an specie from Japan that can also be found at Taiwan, Korea and some regions of China. You will be able to see many of these huge spiders around parks and forests at the end of summer season. I took this picture at Yoyogi park in Tokyo last September. They remind me the “skulltullas” from Zelda, ups! maybe I’m playing Zelda Twilight too much lately.