Very likely given that Naoi seems to have rules she lives by, like how she doesn't snitch on other people. She lied to the teacher to protect Kurumi in the first chapter, by not revealing Kurumi badmouthing her. And Kudou was confident in chapter 20.5 that Naoi wouldn't do something like try to report her for bringing the chocolates to school.
These moments of kindness/consideration for others even threw Kurumi off early on. While Kudou had already assumed that Naoi was in love with her, so Kudou interpreting such gestures through a romantic lense is very likely. And chapter 20 had Kudou seemingly be jealous of how much attention/kindness Naoi was showing Kurumi.
That is a good insight. Especially since Kudou sees Naoi as someone who doesn't feel guilt or vulnerability, there would be no reason for Naoi to be considerate of Kudou other than favoring her.
There may have also been an aspect of Kudou being the only one to understand and accept certain aspects of Naoi. This is why Kurumi is a threat when Kurumi also accepts those aspects, but understands Naoi more fully, allows Naoi to have a wider range of feelings and needs, respects Naoi's autonomy.
It's interesting that we have had maybe four characters take the "You will prioritize me when you have no one else left" approach, if we include Kokoro's home invasion arc as taking advantage of Kurumi's isolation. The other three are Mine toward Isanuma, Naoi toward Kurumi, and Kudou toward Naoi. Naoi still gets to be a sympathetic protagonist because she doesn't try to isolate Kurumi, instead only trying to take advantage of Kurumi's isolation and then becoming fearful when that doesn't work.
