가즈사 국
Two "Nihongi" contexts refer to Watatsumi in legends about Emperor Keikō and Emperor Jimmu. First, the army of Emperor Keikō encounters Hashirimizu 馳水 "running waters" crossing from Sagami Province to Kazusa Province. The calamity is attributed to the Watatsumi 海神 "sea god" and placated through human sacrifice.