Ahoge (アホ毛, アホげ), literally foolish hair, is a visual cue common to Japanese anime and manga. Consisting of a single, often large, lock of hair sticking out from the top of the head, it is most often used to identify foolish, bumbling or carefree characters. In the west, Alfalfa from The Little Rascals would be the most identifiable character with what could be considered an ahoge. Ahoge have appeared on numerous characters but are usually limited to those appearing in works with comedic content and then mostly on females. Male characters with ahoge are more rare but are not unknown, such as Edward Elric from the series Fullmetal Alchemist, Sakai Yuji from Shakugan no Shana, Mashiro from Bakuman, Araragi Koyomi from Bakemonogatari and many characters from the series Hetalia: Axis Powers (North and South Italy for example, whose ahoges are their erogenous zones. Or even South Korea, who has a similar ahoge to the Italy's, only with a smiley face with it).
Ahoge are a naturally occurring trait of the hair and are not created with the aid of styling tools. They also appear only near the top of the head, but can be anywhere on top, front or back. The look of ahoge can also vary widely, from long and thin to short and thick. While ahoge have been seen on characters for decades - Osamu Tezuka created characters with ahoge as far back as 1953 - the first series to popularize the specific use of the term is Pani Poni Dash!. In Pani Poni Dash the character Himeko Katagiri sported one and had a major story line in one episode dedicated to it; Himeko's also appears to be living as it moves on its own and mirrors her current mood.