If this had ended before the last two pages, it would still be heavy dramatic irony (where the audience knows the significance of what's said but the speaker doesn't), but Uta pulling back to face Kaoru directly really ups the ante big time.
Kdramas have a nasty habit of setting up these big pre-revelation moments, then bailing by having the characters say, "Never mind--it's nothing." I really haven't minded the slow build-up in this story (although both the withheld details about the past and Uta's general passivity have been kind of annoying), but, as REDflame23 says, if this scene fizzles into nothing next chapter, well, . . .
[Uta: "The one I like is . . ." Phone suddenly rings. It's Reiichi, checking in to chat. Cut to him in a hotel bed with Risako smoking a cigarette beside him.]
Sorry, I've been watching kdramas for too long.