[1] The song premiered on the JOLF radio program Takashi Okamura's All Night Nippon on November 2, 2017.

[3] The first pressing of the CD single includes an eight-page booklet and alternative cover artwork.

[4] "Yokoku" is Aiko's first single in over a year, since "Koi o Shita no wa" (2016).

[4] Aiko wrote the song to cheer herself up, intending for it to serve as a sort of personal anthem.

"Yokoku" also became Aiko's thirty-fourth single to rank in the top ten.