In the old times in Japan, it was a custom for wealthy families to donate horses to shrines, as part of the invocations and a sign of respect for kami.
In time, this practice changed, first the donations became horse statues and finally changed into small wooden plaques featuring the painting of a horse, called ema.
On these plaques, the worshipers are writing their thanks, wishes and prayers, hanging them on special racks at the shrines, in order to be read by the kami.
In time, the paintings on ema diversified to various animals from Shinto mythology, Chinese zodiac, folklore (e.g. kitsune) or representations of kami:
Since the growth of the popular anime culture, many elements of Shinto practice and mythology appeared in the anime plots so, for me, it wasn’t very unexpected that several years ago, ema started to feature paintings of anime characters.
Follow up:
I saw several anime inspired ema at the Kanda Myojin Shrine near Akihabara, but this didn’t prepared me for what I’ve encountered at the Washinomiya Shrine in Saitama. The Shrine, the oldest in the Kanto region, became famous in the otaku world with the success of the Lucky Star manga. The author, Kagami Yoshimizu, originar from Saitama, choose the Washinomiya Shrine as the place where two main characters, Kagami and Tsukasa, are working as miko.
Here’s an extensive photo presentation of this amazing mixture of popular culture and tradition. I admit, it is strange, but I also find it beautiful…
I am interested in other opinions on this matter… :)
Several cross-overs between Lucky Star and Gundam:
There are also characters from Haruhi Suzumiya:
… and Calimero is here too… :)