So... the Hikawas are finally 18... It's SUPER LATE but happy birthday My goddess and her boppin' sister! I do have a one trillion $ question.................................

WHICH OF THE HIKAWAS is the Elder sister and which is the younger sister!?

I know that Sayo looks older and taller than Hina... But Hina keeps calling Sayo Onee-chan. by Japan's honorifcs law, You are only allowed to call your sister in the suffix -CHAN if you are the elder.. So which statement is true????????????????????

* Sayo is the elder sister

OR

* Hina is the elder sister

?!?

o_O

//head explodes from overthinking about it.