Watatsumi , also pronounced Wadatsumi, is a legendary kami, Japanese dragon and tutelary water deity in Japanese mythology. Ōwatatsumi no kami is believed to be another name for the sea deity Ryūjin and also for the Watatsumi Sanjin , which rule the upper, middle and lower seas respectively and were created when Izanagi was washing himself of the dragons blood when he returned from Yomi, "the underworld".