Uchū no Kioku

The collaboration between Sheena and Sakamoto came about upon Sakamoto being selected to perform the opening theme for BEM, which is a reimagining of Humanoid Monster Bem set in a city modeled after New York City.^[3] Sakamoto voiced a character in the anime, credited as "Mysterious Woman," whose identity is revealed at the story's climax.^[3]

Familiar with Sheena's work since her debut, Sakamoto contacted her to request her involvement on the theme song, believing her musical approach would suit the anime's tone.^[3] Sheena agreed, and she took charge of the entire production of the song, handling its lyrics, composition, and arrangements,^[2][3] and also oversaw all aspects of the song's production, including vocal and instrumental recordings.^[3] Production also featured contributions from the jazz band Soil & "Pimp" Sessions, known for prior collaborations with Sheena.^[3] Their involvement in the instrumental recording complemented the song's jazz elements, aligning with the anime's aesthetic.^[3]

The single's B-side includes a new song, "Jokyoku", written and composed by Sakamoto herself, as well as "Ashita o Shiranai", a cover from her participation in the 2018 tribute album to The Band Apart.^[2]

The lyrics of "Uchū no Kioku" reflect on the themes of BEM, which addresses human folly and the concept of unrewarded righteousness.^[3] The song is written from the perspective of a goddess observing humanity from the universe, combining philosophical lyrics with a jazz melody.^[3] Sakamoto noted that the lyrics were distinct from her own writing style and expressed complex ideas. The melody's rhythm was designed to match the jazz arrangement, creating a unique singing experience for Sakamoto, who initially found it challenging but later adapted to its structure.^[3]

During the recording process, Sheena provided vocal directions, including instructing Sakamoto to sing the climactic chorus in a whisper rather than a powerful style, which Sakamoto found suitable for the song.^[3] Sheena also requested an ad-libbed section in the interlude, where Sakamoto voiced a queen-like figure reacting to humanity’s actions with sighs, conveying both exasperation and affection.^[3]

Writing for Real Sound magazine, music critic Tomoyuki Mori gave a positive review on "Uchū no Kioku," noting how it projects a unique chemistry that only the collaboration between Ringo and Sakamoto could generate.^[4] He further praised the song's "thrilling jazz sound" by Soil & "Pimp" Sessions, its "melody with sensual allure," and its "lyrics that fully leverage the beauty of the Japanese language."^[4]

"Uchū no Kioku" debuted at number 21 on the Oricon Weekly Singles Chart,^[5] selling 4,665 copies on its first week.^[6] The single charted for four weeks, with reported sales totaling 5,865 copies.^[7]

Credits adapted from the liner notes of the "Uchū no Kioku" CD single.^[1]