Green fn comes from basketball gaming slang for a green, perfect release, a phrase that blew up on TikTok in early 2024 and quickly became shorthand for calling a guaranteed success. Editors soon attached it to smug fictional characters, and Gojo Satoru from Jujutsu Kaisen fit perfectly because fans already edit him as untouchable and arrogant. The Gojo version spread through anime edits, gaming clips and basketball posts in the same spaces as goku drip, and it stays popular because the phrase instantly signals confidence before a payoff.