Oni is one of the most popular and common imaged animals in Japan.
It often appears in folklore, childrens storys, festivals
and traditional annual events.
There are some variations,
but most common oni has one or two horns on its head,
big fangs with its upper or under jaw and scarlet-faced or blue-faced.
They are naked except for tiger-skin loincloths (or short pants in recent years)
and carry very large heavy metal clubs with many spikes.

*According to the yin and yang, it has been said that North-East is t
he worst direction in Japan.
The North-West is Ushi-Tora (lit. cattle-tiger) in old terms.
As cattle have horns and a tiger has yellow and black striped skin,
people imagine that oni have one or two horns and wear tiger patterned pants.

Now there are abhorrent images of oni.
Some have traditionaly been bad images and
still they are a symbol of evil that devour people.
In the early 8th century they appeared as ferocious and fierce demons
in hell or the land of the dead people
in the chronicles ( Kojiki and Nihonshoki).
Whereas, because of the influence of the thought of Buddism
and cult of the god of thunder, there are also images of oni
who are humorous, friendly
and bring good fortune to people.

If you are very interested in Oni, I recommend you visit
Ooe-yama (name of the mountain ) in Tango region in Kyoto Pref.
( according to another story it's Tamba region in Kyoto Pref.)
You can meet lots of oni there, :))
in Osu-kannon

There are five kinds of oni
in five colors.
Each color has some meanings:

red avarice, greediness, devour
blue anger, irritation
black complain, waver, hesitate
green arrogance, excite
yellow impose, repine

Tiger stripe pants is
oni's uniform : ))
with a metal rod

and are the most important items for