NMIXX released O.O in February 2022 as the title track of their debut single album Ad Mare, introducing the South Korean group with their genre-switching mixx pop style. The song and its music video quickly drew attention for its abrupt changes and confident performance, and short clips from it began circulating in fan edits and short-form videos. Fans still reuse the call-like opening because it instantly signals NMIXX, sets a high-energy tone and fits the fast pacing of modern K-pop content.