well i can see what you are talking about but the fact that the sister died when they were very young and they can barely remember her and then Hari and Eugene spent a lot of time apart due to the parents passing away, its logical that they do not see each other as relatives but more as close acquaintances and then as possible love interests #-.-)
dude idk if you're serious or just making excuses now but you're telling me you need spoilers to confirm they have feelings for each other? not like each chapter of the manwha doesnt imply they have romance tension or feelings for each other. ok ig you dont get context clues. have a nice day nightowl :)!
....So the spoilers are true and I can't help but feel grossed out! She looks like his dead sister! She's his adopted sister and now they're getting together???