Fujiko begins work as a teacher at an all-girls school, where she immediately finds herself the target of affection for many of the students, including a shy girl named Isolde Brach. Fujiko starts to take an interest in Isolde and the two spend some time together. As Isolde is punished by her jealous classmates, she turns to Fujiko for a night of passion. However, it is soon revealed that Isolde is actually Zenigata's assistant, Oscar, who took the real Isolde's place in order to catch both Fujiko and Lupin. The next day, Oscar initiates a plan to capture Lupin. However by that time, he had already freed Fujiko, who tricks Oscar into giving her the code for a pendant containing a thesis by Isolde's late father. As Fujiko and Lupin escape and share the spoils, Oscar swears to get revenge on Fujiko.