This is the first studio album released by the band Yorushika (stylized ヨルシカ), a J-pop/J-rock group made up primarily of songwriter and composer n-buna and vocalist suis, along with other credited performers on various instruments. The album is framed as a collection of letters and songs written by a musician named Amy, and left behind after he commits suicide. The intended recipient for these mementos is a woman named Elma, herself also a musician, who was once close with Amy. It's heavily implied that she took the lyrics and letters Amy left her and set them to music, performing them in her own voice and with her own imagination of what Amy was going through.

The "intended" reading of the album is alongside a slideshow of photos and letters, ordered as if they're being pulled out of the box Amy left them in one by one. This slideshow is hosted on Yorushika's website: https://yorushika.com/feature/moonlight

I've ordered the tracklist as it is both in this slideshow and on music streaming services / the album's liner notes. However, the letters themselves, and the dates on which the songs were written, are jumbled chronologically. Still, they're grouped together in envelopes that suggest what "section" of the album they belong to, so I've preserved that order even when it's confusing.

Overall the dates on the envelopes suggest a working backwards in time, from Amy's final letters back to his earliest.