Ikenai Borderline was released in 2016 as the debut single by Walküre, the fictional idol unit from the anime series Macross Delta. The girigiri eye phrasing comes from the song's teasing chorus about love on the edge, sung in character by the group's vocalists. Clips of the hook spread through anime edits, rhythm game circles and social video, where its short dramatic burst became easy to reuse. It remains popular because Macross fans recognise it instantly and newcomers hear it as a catchy, exaggerated anime pop moment.