so we know the Hiyugas have all that shit with the cursed seal on the secondary branches of the family right, that's a big think on neji lore and all

but I was thinking

neji is not just a random Hiyuga that calls hinata cousin because they technically share blood - his dad is literally hinata's twin

now, hinata is the heir to the Hiyuga clan, and her dad is the head of the family, which make them the main branch

for hinata's dad to be the head of the clan, he too must have been born as part of the main branch, which makes his twin sibling also part of the main branch

if we stop right there, that makes neji, hinata's cousin, a direct descendant of the main branch just like her - so why is he treated as a secondary branch and receives the cursed seal?

one might argue that neji's dad was a second born, so he was the moment of ramification into a new secondary branch, which seems to be how the Hiyuga family operates - in that way, he, being a second born, received a cursed seal branding around, I'm guessing, the same age as neji did, four or five

so, we establish that only the eldest child stays as part of the main branch, which establishes hinata as the heir

now, pray tell, if this is the dynamic of this very old and conservative clan, WHY THE FUCK DOESNT HINATA'S LITTLE SISTER GET A SEAL ON HER FOREHEAD

of course, I wish for no character this curse, but given the family operational customs, Hanabi should have received a seal, no? she's uncontestably the younger sister, and she is already four or five by the time naruto classic rolls around, on top of being incredibly talented to a point where she'd be a risk to her older sister command on the house in the future