Much of the song's production is similar to the Japanese version; it was written and composed by Utada, whilst production was handled by Utada, her father Teruzane Utada, and Miyake Akira. The song included live instrumentation by Kawano Kei (keyboards and programming), Tsunemi Kazuhide (synthesizers), and Akiyama Hironori (acoustic guitar), whilst it was arranged by Utada and Kawano Kei. The song was recorded by Ugajin Masaaki and mixed by Goh Hotoda in 2001 at Bunkamura Studio, Shibuya, Tokyo. The song was also remixed by Russell McNamara (under the alias PlanitB). Like the Japanese version, Utada felt the writing process was difficult. Musically, "Simple & Clean" is a pop folk song, as described by staff members from Japanese music magazine "CD Journal". Utada explained the song process in a detailed interview with "Jetanny Magazine";