His hidden sister
The host know almost everything about Kyoya or they think they do. Tamaki his best friend knows just about everything there is to know about Kyoya, who his family is and how they treat each other but what Tamaki doesn't know is that Kyoya has a younger sister. Kiku was hidden away after an accident several years before Tamaki ever met his best friend and she is finally making an appearance in the world. How will the host club react to this well kept dark secret that Kyoya has kept from them? Will one of the host fall in love with Kiku? Will Kiku find acceptance from someone other than her beloved big brother?…