I can understand that, and you're completely right. It is real and I used to have a relationship like this so I relate. :-[ There was no development with him and his big sister as well as the main couples development. It would've been nice to at least have a full bdsm scene. She asked for a slave&Master relationship without having lust or knowledge. :'( The story had so much potential!
Regarding the lack of developments, I'm just guessing but it's likely that the whole plot idea; BDSM clashed w the bittersweet ending which the author had probably decided for a long time ago... But then again, that's just my guess I agree w you that the story had so much potential w the BDSM plot, but somehow everything about it seems like a supporting plot instead because of the faint tragedy leading the protagonists elsewhere? Either way, thanks for sharing your thought mate!! ε=ε=(ノ≧∇≦)ノ
The ending was good for me though, yall? It's definitely rushed, but if we're taking it from a certain perspective like 'the ending manuscript' that the author had decided, it's actually pretty good. It takes a lot more to see the ending plot in the positive way without seeing the lacking of story dynamics though... Either way, I love how this starts off from characters' youthfulness and end in the stage where everyone had learn from their past experiences. The realism in this manhwa is what I favour the most. I highly recommend this manhwa... To those who favours bittersweet tragic story values and endings where readers can interpret the epilogue and overall message from the author
It's a five out of five stars for me