Izanagi and Izanami are about to pair up and marry. They don’t know how to do it though.
At first, Izanami, the wife, took the initiative in the courting. And the result is called Hiruko, a deformed child born without hand, feet, or bones. Seeing the child probably wouldn’t make it, the couple put him in a reed raft and cast him away to the sea. There’s version of myth where he did came back as Ebisu, the good luck god of fisheries and mascot of Ebisu beer brewery. Yes, same kanji as the Ebisumori main family, meanwhile Namu’s branch family’s name is written with Hiruko, but read as Ebisu.
They asked the older gods about what went wrong, and got told they get the order wrong. It should be the man who initiate the courting, not woman (yes, I know, very patriarchal, but that era). This time the husband initiated the courting and they give birth to normal gods.