I am amazed by the culture here in Okinawa and have delightedly found one which honors the spirits with such dedication. What am I talking about? Well in mainland Japan it's been Shinto that dominated for most of their history, followed by Buddhism. That's not the case here in Okinawa. Here while they have borrowed elements from both they primarily a shamanistic practice that is held in common with the other Ryukyuan islands...but I'm getting ahead of myself.
The first thing you will notice on approaching any building is the Shishi, Shisa, or Shisha "lion dogs" paired at either side of the primary entrance. On the right one with it's mouth tightly shut. On asking it is to keep the good spirits within the house. On the left, it's mouth is open with teeth bared - which drives out evil spirits. They take great stock in these even if they aren't otherwise religious. To me as a grimoiric mage working with the Verum and the PGM, I find this fantastic and otherwise awesome. Origins of this statue was of ultimately 14th century Chinese origin, and was originally just one statue, not the pair. With the coming of Buddhism, the view of some spirits could be "bad" spirits the addition of the second Shisha was added to perform the necessary talismanic exorcism of the home. From this it grew into many stories about it's origin. Here is one of them:
"A small boy was given a clay shisha as a gift from an Okinawan nobleman. One day, a dragon appeared out of the ocean to destroy the village. The clay shisha came to life and saved the village and that is why shisha's are used to ward off evil spirits."
I see in this a similarity to the household gods of the ancient Greeks and Romans, nor is this the only instance of this in the traditional home. Ancestor worship is big here - really big. Your own immediate ancestors no more than 25 generations back are revered in the home at a little cabinet called the buchidan. Here the family's altar is sheltered within where plaques of family member names are held and offered incense, alcohol, tea, water, cooked rice, - and on festivals tropical fruits and sake. A hearth god, Hinukan is also given a place (usually in the kitchen). His shrine is three stones. I've heard of both genders for this hearth god, but from different sources. The noro (community priestess) officiates his/her worship. The Hinukan is said to inhabit the family home, but it is not the Hinukan's home - which he/she leaves to travel to during the solar new year. Finally, yes, the Okinawan's have a "god of the toilet" Furu nu kami - to worship this god keep the bathroom clean. This god gets rid of things plaguing the family and is given regular reports on how the family is doing.
The other spirits of the world are generally all lumped into one term - 'kami' which means spirit with a neither good nor bad descriptor. Youkai are the negative or spirits prone to mischief.
The other ancestor spirits are worshiped by the community - ancestors 25 generations back usually in Buddhist temples, and the ultimate ancestors (father, mother, and sea) which are worshiped at sacred natural places called Utaki where the ultimate ancestors and the kami are revered.
More coming - for now I'll publish, with additions and revisions as necessary later today. Enjoy!