It is world where is much bigger female population than male one. So you mostly see girls or women around, not men. You go to all girls school, where are few places for boys, too. Number of boys is too small and rare to make a special school just for them. You have nine sisters and you are their only one brother. And it is pretty normal for this world. Now it is night party time so you walk your nine sister to the night party, after all you will need to walk them all home safe with you.