: Some references suggest "Shoetsu Otomo Reona 44" may be a title for specific artworks or posters used as props or lore within the story itself. One account describes a faded poster in a bar with this exact inscription, serving as a nostalgic or symbolic backdrop for the characters.
: A popular "despair-style" anime singer signed to Sacra Music , known for her work on Sword Art Online . Her aesthetic of "Hello, Unhappy" and her focus on finding light within darkness mirrors the themes of identity and survival found in the Shoetsu Otomo novel.