I feel like when a story starts with the siblings being normal siblings it's usually when they have different hair/eye colors that they are BR and when they actually look related then it's NBR with few exceptions. It's honestly kind of infuriating, looking at you Futago-tachi no Shojijou lmao.
Sorry! I know it's been a while, life just gets in the way
But no matter what, I still plan on finishing the manga (even if it takes a little while )
+ I'll be uploading the next 2 chapters by the end of the week so stay tuned