The opening and ending sequences feature artistic drawings of the principal characters. These characters are drawn in a style based on Gustav Klimt's paintings, including "The Kiss", "Adele Bloch-Bauer I", and others with similar imitating poses, colors, and patterns. In promotional art as well as in the series itself, characters make use of a famous El Greco hand symbol of outstretched fingers with the middle and ring fingers connected. The song "Elfenlied" ("Elf Song") appears in the manga and is credited to the composer Hugo Wolf. A poem by Eduard Mörike is the basis for Wolf's version. It is taught to Nyu by the manga-only protagonist Nozomi.