can't stop thinking about them making someone confess to nanaki on the emergency staircase that kiroku introduced him to (giving it romantic connotations) and making kiroku witness it...... especially since the only time we've seen kiroku smile in a staircase scene was after nanaki called it their secret hideout
i like to think kiroku doesn't really question his feelings for nanaki. he likes spending time with him, whether it's coffee sessions in their room or the cafes nanaki takes him to (just their normal day to day things) but he especially likes meeting nanaki at the emergency staircase and hearing nanaki call it "their spot". sometimes being around him makes his chest feel a little funny, but he never stops to think about why. in the end he's happy, so there isn't really anything to examine
part of that is because of how (pre-imaginatio) kiroku had initially seen nanaki as someone completely different to himself. he saw nanaki as popular, talented, sociable, loved by everyone while kiroku was withdrawn and used to being misunderstood (thinking about the scene in the main story where kiroku doesn't believe nanaki really means it when he says he likes kiroku's lantern, and that he's just saying it to be nice cuz well. he's popular). but the events of kiroku's feature tour and the song nanaki makes for him bring them closer and makes kiroku realise they have more in common than he initally thought. kiroku showing nanaki his secret spot is him letting nanaki into his world all over again. i like to think nanaki gradually stops feeling like "the popular guy everyone likes" and starts feeling like just his friend and roommate nanaki, with whom being around feels as easy as breathing
but then one day kiroku arrives at the staircase and sees a girl confessing to him. it's unsettling, because it suddenly reminds kiroku of the nanaki that exists outside of their little world -- because at this point in time, kiroku doesn't really know much about romance. it's a whole separate world he'd never considered venturing into and has never really had anything to do with him. nanaki's refusal to try things out with her doesn't really make sense to him, but he can tell by the certainty in nanaki's voice that nanaki knows exactly how he feels and where he stands. listening to him reject her, kiroku realises that nanaki seems to understand something he doesn't. it's something kiroku has actually been hearing all along in nanaki’s songs but never thought of as anything more than just music that made his heart stir. for all the ways the distance between them has shrunk, there's still this whole world of feelings and relationships that nanaki navigates with ease in a way kiroku believes he can't relate to
i think this asymmetry would naturally recolour everything retroactively. suddenly kiroku's seeing nanaki as a romantic possibility for other people for the first time. before nanaki was just the nanaki he's come to know, but now he's forced to look at him through someone else's eyes and starts to notice things he'd previously never thought to look deeper into, like the fact that nanaki is objectively handsome. the things that he's always considered to be ordinary parts of nanaki -- like his smile, his voice, the pretty colour of his eyes -- are things other people might immediately fall for... and slowly but surely he starts to realise why his heart would flutter a little when nanaki modelled for his drawing that one time, and that all of this may be contributing to the fuzzy feeling he feels around him overall (i feel like pinfu would play a significant role here)
idk where i'm going with this but i feel like after that first crack it's harder for kiroku to stay in the same kind of not-knowing he used to live in. nothing between them changes on the surface -- nanaki still shows up to the stairs and calls it their secret spot -- but kiroku starts noticing the way the familiar fuzzy feeling stops feeling neutral and instead much more specific. it begins to settle in him and quietly reshapes the way he understands every ordinary moment they share
somewhere along the way kiroku realises that what he feels isn't just comfort or closeness and that it's something more akin to what nanaki writes songs about. the imbalance he felt earlier was never really about nanaki being out of reach but more about kiroku not yet having a name for what he was feeling. once he understands that, he starts to realise it’s love, even if it takes him time to fully accept it.