Kira is the alias Light Yagami uses in Death Note, the manga series that ran from 2003 to 2006 and was adapted into an anime in 2006. As Light grows more ruthless while evading investigators, his confident persona cracks into open villainy, and clips of his laugh were shared on YouTube and soundboards as a shorthand for maniacal triumph. The clip endures because anime fans instantly recognise the voice and character, while other viewers still read the escalating cackle clearly as an evil mastermind celebrating a win.