So it's basically Suguha again where in all likelihood the sister learned that they're not blood related and is confused if her feelings for him is maybe romantic when she thought it's been familial before.
Oh fuck this pussy shit, the whole non-blood related shit is litteraly always just 'i don't have the balls to actualy own up to my story', the whole story is pointless now because there is litteraly no reason they shouldn't fuck right now.
I was hoping it would be a scenario where he and Uiha are blood siblings who were both adopted together, that's why he's so attached to her cuz she's the only "true" family he has. Meanwhile she's just going thru teenager shit and the tsundere-ness is a phase.