The first self-cover album commemorating Akino Arai's 40th debut anniversary. It contains 15 songs that are especially meaningful to her, mainly works from shortly after her debut in 1988 through 2004, the first half of her career. In the Resound all songs live series held from 2025, she attempted to perform each of her first four albums in full, one album at a time, nonstop without MC segments, and this album is based on the live arrangements created for those performances by her longtime production partner Hisaaki Hogari, further developed into an album work. In addition to still-popular songs such as "Moon Light Anthem - Enju 1991 -" (image album for the comic "Please Save My Earth"), "VOICES," which is highly popular overseas ("Macross Plus" soundtrack, composed by Yoko Kanno, lyrics by Wakako Kaku), and "Kakusei Toshi," the ending theme for the TV anime "Tokyo Underground," the album also contains "Tale of Blue," a song created for Yui Makino in 2022, arranged by Arai herself. For the jacket, Hanaco (Hanako Takeuchi), who creates the costumes for every one of Arai's live performances, handled the costume, hair and makeup, photography, and even the artwork, richly expressing the worldview of Akino Arai that is also represented by the title "Akinosphere." The recording features kidlit, who produced the final performance of the Resound all songs series, on keyboards, as well as Sakana Hosomi on keyboards, Manabu Chigasaki on bass, Masahiko Todo on violin, and Takahiro Yuki on cello.