The sound comes from Ninja Slayer, the Japanese novel series adapted as the 2015 anime Ninja Slayer From Animation. In that deliberately overblown world, Clone Yakuza are disposable mass produced enforcers, so their deaths are quick, loud and played for dark comedy rather than tragedy. Fans clipped this short death moment and shared it on soundboards, where its abrupt timing made it useful far beyond the show. It remains popular with editors who want an anime kill to feel both brutal and ridiculous at once.