@lilisionnach @nims The translation was a little rough because of the terminology (literally for part of it: "my father is the son-in law," which was a little difficult to understand), but what I understood was
both momo and riko were from the first marriage, but since momo was used to being called by Naoe (since surnames are much more commonly used), she goes by it
or that Momo was born and named before the remarriage, and then I think Riko was born, or something like that. No indication of being step-siblings, at the very least
and
@0ps I feel u, makes translation even harder