WARNING: There might be some spoilers related to the appearance and function of spirits encountered later in the series.
I was thinking that the spirits shown in Mokke might be just the creators' imagination for a while. So I decided to dig out some information about japanese ghosts/spirits (Obakemono). Looks like both
Izuna and
Mikoshi are spirits which appear in the actual japanese mythology. And what are they according to it?
Mikoshi Mikoshi/Mikoshi-nyuudou (見越/見越ã—å…¥é“)
Nyuudou is a kind of
youkai(demon/spirit), which looks like a
young wandering Buddhist priest. You can encounter him at lonely roads. If you
look at him, he starts to grow - the higher you look, the higher he grows. You can get rid of him by shouting "Mikoshita!" or "Minuita!" which means "I've seen over you/through you".
Mikoshi according to a famous Edo period (1603-1968) artist Toriyama Sekien.
Izuna Izuna, Kudagitsune (飯綱, 管ç‹)
Izuna is a type of fox-magic used by a cult worshipping a
tengu named Izuna-gongen. It is also a word reffering to the actual
kudagitsune.
Kudagitsune is a word created by combination of Kanji characters for a fox and a tube.
Kudagitsune is a spirit looking like a fox of size of a mouse. It can be summoned by a sorcerer into, or can possess a bamboo tube. If controlled by its summoner it can answer any question it is asked. It also likes miso (soybean paste) a lot so it can make the possessed people eat miso all the day. If taken out of its tube, it can make a lot of misfortunes to the possessed person and his village.
Another version of
izuna/kudagitsune coming from the Shinano province is a mouse sized creature with its tail looking like a tube cut in half.
It can be tamed and kept in a pocket or sleeve, and uses its supernatural power to seek out assorted information which it then whispers to its master. A person who keeps it is thus able to see into both the past and future. (
wiki)
Kanko(管ç‹) is another way the
kudagitsune is called.
That’s about it. There are a lot of information contrary to each other because people in each province imagines a little different versions of every
youkai. There are even at least two versions of the famous
Tanabata (
version2) story.
The Obakemono Project
EDIT: various links