アホ毛, literally, "stupid hair". A single (usually short and fat) lock of hair that sticks out of a character's head. Also known as a Cowlick. The character is usually stupid in some way, but there are enough exceptions that this isn't a rule. Example characters include Himeko and Me-tan.
To be differentiated from antenna hair, which is two or more thin locks of hair as opposed to only one.
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