"D" is an intelligence agent dispatched from an alien spacecraft that crashes on Earth. Operating under Captain Napolipolita's command, she participates in the aliens' project to rebuild their damaged vessel into a commercial entertainment venue. Possessing a notably muscular and imposing physique, "D" is initially perceived as male, a misconception later revealed for narrative effect. Although she demonstrates considerable physical strength during operations, her capabilities remain inferior to protagonist A-ko's superhuman power during their encounters. Within the storyline of *Project A-ko 3: Cinderella Rhapsody*, "D" contributes to maintaining order at the transformed space hotel when conflicts erupt between rivals A-ko and B-ko over Kei, aligning with the alien crew's broader efforts to manage disruptions to their establishment.