長尾大
Under the concept of "Whoever the songwriter is, it is D.A.I", the credit was written as "D.A.I" at first, even if any other member would compose the music. After "Be Free" was collected in "Do the B-side", it came to be specified who wrote a song, and, after re-formation, it came to be specified who composed as well. Tomiko Van and Ryo Owatari mainly write lyrics. Saiko Kawamura, which is a joint nom de plume of Jun Harada and Kayoko Shinchi, and Naoto Suzuki also write songs besides them. It seems that Dai Nagao composed almost all the music except for "Azayaka na Hana" collected in "Gates of Heaven", which Ryo Owatari composed. They produced the first and the second singles by themselves, but Seiji Kameda became a joint producer from the third single; he also plays a bass guitar in recording.