They were thought to have special powers and are often portrayed that way in anime. Stories made specially for release on video rather than TV or in theaters. Almost all popular anime shows have OAV's. T rack Otaku - Japanese word meaning obsessive fan of anything. Somewhat derogatory meaning that you put your interest above all else.
Westerners tend to use it without the derogatory connotations.
Formerly the abbreviation for r ec. It is now broken down into nine categories due to increase in popularity. Redisu - Ladies Manga. Often grouped with shojo by westerners. Often used in anime when adressing royalty.