Kusanagi and Kishitani visit the Marian Nightclub near Kinshicho Station. They meet with the club's mama, a woman by the name of Sonoka Sugimura. They ask her for information about Kudo, and she explains that, based on her judgment as nightclub mama, Kudo's relationship with Yasuko had been strictly platonic. Furthermore, according to her, Kudo had been advising Yasuko on how to seek reconciliation with Togashi. All of this confirms Kudo's innocence in the matter of Togashi's death, which is consistent with what Kusanagi believed about Kudo's role in the case as well.

Sonoka further denies having any knowledge of Ishigami, which makes it less likely that Ishigami could've been an accomplcie to the murder of Togashi. In fact, Sonoka goes so far as to reject any notion that Yasuko might've been involved in a relationship with any other man. This makes it even more difficult for them to maintain the theory that Yasuko had relied upon a male accomplice for help.

Curiously, Sonoka mentions a phone call that she had received from Yasuko on the night of March 10 around 11 p.m., right after Yasuko would've returned from karaoke with her daughter. Sonoka returned the call after midnight, talking with Yasuko for half an hour. It turns out that Yasuko was merely interested in the name of massage place. According to Sonoka, it wasn't unusual for Yasuko to call Sonoka at such a late hour and inquire about such commonplace matters as these.

The fact that Yasuko had failed to mention this phone call under police questioning fails to make sense for Kusanagi since such a phone call would've been worth mentioning given her need to provide an alibi for March 10. At the very least, the phone call disabuses Kusanagi of the notion that Yasuko might've committed the murder in the middle of the night (after coming back from the karaoke place), a theory which had been entertained by some members of the police force but which now seemed untenable.

Perplexed by the fact that Yasuko had failed to disclose information that would've been relevant to her alibi and therefore helpful in exonerating her of suspicion, Kusanagi recalls Yukawa's interpretations of the case, which presuppose Ishigami's inability to make careless mistakes in covering up the murder. From the standpoint of Ishigami's genius in dealing with matters in logical and foolproof ways, it seems unlikely to Yukawa that Ishigami would've committed murder, as such a deed wouldn't have been the most logical course of action in helping to protect Yusako. Given this insight, Kusanagi can't help speculating whether or not Yasuko's failure to disclose her late-night phone call to Sonoko was by design, following a pre-arranged plan devised by Ishigami. This only enhances Kusanagi's respect for Ishigami as "an adversary to be feared," as opposed to being a novice murderer whose ineptitude could be invoked as an explanation for the more perplexing aspects of the case.

The narrative shifts to the lunch box shop where Yasuko, getting ready to go home, is visited by Yukawa. At the insistence of Yukawa, she walks back home with him accompanying her and asking her questions about her relationship with Ishigami. Yukawa inquires into the nature of Yasuko's relationship with Ishigami, specifically what is was that might've made Ishigami take such an interest in Yasuko. However, Yasuko is at loss when confronted with this question, since she herself hadn't really considered why Ishigami was so enamored with her to begin with. Yukawa's probing questions and comments show a degree of familiarity with Yasuko and Ishigami's relationship that makes Yasuko extremely uneasy and also less comfortable in maintaining the pretense that she barely knows Ishigami. As Yukawa departs, Yasuko is left with a deep impression of Yukawa's forceful and commanding presence, which makes it hard to avoid or resist his questioning.