This combines black metal, death metal and thrash metal elements with traditional Japanese influences, not only musically but also lyrically, especially with references to gods in Japanese mythology such as Izanagi and Izanami, and also the Japanese version of Hell known as Yomi.
Ashihara no Nakatsukuni, in Japanese mythology, the world between Takamagahara (Heaven) and Yomi (Hell)
There is also a rarer prefix mi- (kun'yomi), which is mostly used in words related to gods and the emperor, such as mi-koshi (御輿, "portable shrine" in Shinto) and mi-na (御名, "the Holy Name" in Christianity).
Meir Shapiro, dean of Chachmei Lublin Yeshiva, and founder of the Daf Yomi Talmud folio cycle
Note that in addition to reading 海神 as watatsumi, wata no kami, or unagami in native Japanese kun'yomi pronunciation, it is also read kaijin or kaishin in Sino-Japanese on'yomi (from Chinese haishen 海神 "sea god").
Yomi (読) in her first name means reading in Japanese, while -ko (子) (literally 'child') is a common suffix in Japanese female names, so her first name means Reading-woman.