Mark from NCT, a K-pop boy group under SM Entertainment, made his solo debut with the release of his first single, "200," which features a rock sound with fast-tempo bass and drum elements. Mark was involved in writing the lyrics and composing the song, which revolves around a serendipitous encounter leading to a radiant relationship. The music video for "200" incorporates a vintage aesthetic with cartoon elements, evoking a nostalgic early 2000s vibe. Additionally, an acoustic version of the song was also released, showcasing a mellower melody and vocals. In a statement, Mark expressed his excitement about sharing the single with fans and highlighted the soothing quality of the acoustic version. He also mentioned the visually captivating aspects of the music video, emphasizing his enjoyment during the filming process. This release marks the beginning of Mark's solo endeavors, with plans for his first official solo album to be unveiled in February 2025.