This sound is based on Bokuto Koutarou, a fan-favorite character from Haikyu!!, the volleyball manga and anime series. His upbeat "hey hey hey" became memorable among viewers because it matches his loud, excitable personality. The clip spread through anime edits, reaction videos and short meme posts where creators needed a fast burst of confidence or hype. It is still used because even people who do not know the full scene can immediately read the energy of the line.