- All for Nothing: The jeweled mask burns up in the fireplace. Given it was all part of a impoverished couple's plan, it's very probably costume jewelry.
- Boxed Crook: Fujiko becomes this, though neither Zenigata or Fujiko take the deal very seriously.
- Corrupt Cop: Played with. Zenigata is straight as an arrow but has sex with Fujiko as part of their "deal."
- Expy: The Ghost for the Phantom of the Opera.
- Happily Married: Ayan and Dorenzo.
- The Immodest Orgasm: Fujiko does this when having sex with Zenigata, though the latter knows and points out to her afterwards that she was faking it.
- Sex for Services: Fujiko barters sex with Zenigata as part of their deal.
- UptownGirl: The reason Ayan's relationship with Dorenzo was disapproved of.
- Well-Intentioned Extremist: Ayan really did burn half her face off to make sure the plot went off without a hitch.
- Whole Plot Reference: One for the Phantom of the Opera with minor changes.
Recap / Lupin IIIS 4 E 4
In order to be released from the police, Fujiko has sex with Koichi Zenigata and is then told to protect a jewel studded mask worn by an opera singer named Ayan Maya from being stolen by Lupin. As the performance goes on tonight, a mysterious 'ghost of the opera' makes an attempt on Ayan's life. As Ayan faints from the experience, Fujiko is cast as her stand-in to draw out Lupin. However, Fujiko is soon trapped, discovering that the attempt on Ayan's life was a fake, while Lupin reveals the Ayan on stage is actually a stagehand. As Zenigata chases after Lupin, Fujiko chases after the ghost, Darenzo, and meets the real Ayan, who had been living underneath the opera house with Dorenzo. As Ayan explains the decisions she made, she decides to burn the mask before inviting Fujiko and Lupin to join them for dinner.