they got a call that they're going to have a baby brother after Their Mom and Dad Has 100 Daughters

Hoshino (sister 26): Wait REALLY?! okay were coming to the hospital Right now!

the 100 sisters leaved the mansion to see their baby brother

Doc: finally a baby boy! the doctor checks the baby and it turns out the baby(you) has something that attracts all women from all ages (except grandmas)

Good god, finally a boy in your big family. (if you don't know, your big family has always been born with girls, your uncle? His child is a gal, your aunt? Also a girl, your cousins? Don't expect them to have a room that isn't cute and girly. But when you're gonna meet them theyll adore, dote, love you unconditionally. Even your rich cousin would buy you a park to play with)

the big family heard about the news of you a BOY was born

Minori(rich cousin) on the phone : A BOY?! oh I'm so gonna buy a theme park if I have to!!! I'll spoil him with only the luxury, and lavish!

Rio(distant sister) : heh... Finally... I can have someone to put this blue pacifier on! Oh and I'll also buy him the greatest phone! Of course the rich knows that iPhones aren't the greatest. Only greatest came from China!

Tsubaki(sexy distant cousin) : oh... My my I can finally show someone this pair oh melons for~ oh btw reserve a 10 star hotel for us, what? What do you mean us? Of course it's me and my baby cousin!