ESCHA CHRON

The "heartwarming" anime's story follows the two titular women Escha and Chron, whose contrasting personalities are like the sun and moon. The two women are from "Terminal," a future post-apocalyptic world that's empty and monochrome. The two women cross worlds and arrive in the present day, which they call "Transit." As Escha and Chron experience the light (scenery) and sound (music) of the real world, the future world of Terminal gradually changes into a more vivid world. (Source: Anime News Network) — Description from AniList community (anilist.co).