Niko Niko Nii comes from Love Live School Idol Project, where Nico Yazawa of the idol group Muse uses it as her personal greeting and stage catchphrase. She pairs the line with a hand gesture and a wide smile, presenting it as her brand. Clips spread through anime fandom in the mid 2010s on YouTube and later TikTok, often alongside other cute catchphrases like Tuturu. Its exaggerated cuteness made it a lasting shorthand for idol culture and ironic kawaii humor.