Searching about the differences between Japanese dragons and Chinese dragons I found this interesting article about how many toes has the Chinese, Korean and Japanese dragons:
Chinese dragons have all five toes. The Chinese believe that all dragons began from China. They believed that as the dragons flew south, they began to lose their toes. The farther the dragons flew, the more toes they lost. So, Korean dragons have four toes, and Japanese dragons have three.
Korean dragons have four toes. The Koreans believe that when the dragons leave Korea and go north to China, they begin to gain toes. When the dragons leave Korea and go north to Japan, they begin to lose toes.
Japanese dragons have three toes. The Japanese though all dragons originated from Japan. They also believed that when the dragons leave Japan and head north, they gain toes. The farther the dragons went, the more toes they gained. This is why the other dragons have more toes. The Japanese believed the breath of dragons could turn into clouds, which could produce rain.
But here's the kicker, unlike most types of dragon, most of the Eastern Dragons have no wings!"