There is a legend which says the eight lightning gods were charged with protection of the Dharma by the Buddha. This kind of syncretism is not unusual in Japan, even after the Buddha-kami separation order. The iconography of the Raijin and Fuujin gods has been heavily influenced by Buddhist art, itself influenced by Greek and Indian art.
Some Japanese parents tell their children to hide their belly buttons (or navels) during thunderstorms. This is due to a folk belief that Raijin is sometimes credited with eating the navels or abdomen of children, and in the event of thunder, parents traditionally tell their children to hide their navels so that they are not taken away. Raijin's companion is the demon Raiju.
In Japanese art, the deity is known to challenge Fujin, the wind god.