How did this happen
It's possibleOnii-chan, this person… could she be crazy?
Years late to make this statement, but Japanese uses similar terms for step-relations and in-law relations. Also, weirdly, the shortest description of their relationship is that she's his brother's sister-in-law or his sister-in-law's sister; neither English nor Japanese nomenclature accords a special term for your sibling's spouse's sibling.Step-sister? What are you talking about, from my understanding that makes her your sister-in-law not step-sister.
It's funny how the neighbor got swept up in FMC's nonsense