Actually, it doesn't even feel like it's parodying NTR archetypes at all. It just feels like an average reverse harem. And I wouldn't be surprised if that's how it ends, with the MC just getting a full harem of cute guys rather than NTR whatever.
- bashful & sensitive Childhood Friend
- sporty charismatic & attractive guy
- shota in this very chapter
without even getting into future events from the novel, those are
all elements of NTR stories, and the specific tie-ins of how they interact and exist through the lens of Reiko makes this a definitive example of NTR trope usage.
Whether or not it
resolves them, either faithfully to the NTR genre or in some subverted fashion, is up for debate. But your first sentence is categorically incorrect, in only by virtue of the protagonist herself and the her meta-contextual interactions with the characters, setting, and story itself.