Mizuko

A mizuko (, mizuko, lit. "water child") is a miscarried, stillborn, or aborted child who died before or shortly after birth. Nora is the only known mizuko in the series currently.

In Noragami
Mizuko in the series still possess a soul, as it was remarked that Nora's "tiny soul" was touched by a phantom. They have no concept of right and wrong, and giving a mizuko a name is akin to giving them the life they did not have a chance to live.

After giving Nora the name "Hiiro", Yato sees what should have been her memories: darkness (likely that of the womb), along with a consistent "boom" (possibly a heartbeat), and speech bubbles that imply unclear or muffled voices.

Cultural References
[TBA]