Ouran Highschool Host Club: Secret Relationship(Kyoya X Oc)

Kimiko is Tamaki's twin sister, she keeps an eye on the host club for Their father to make sure Tamaki doesn't do anything stupid. The pulse side is that she get to spend time with her boyfriend Kyoya Ootori, well they are actully engaged. The problem is that Tamaki doesn't know that his best friend is dating his sister. How will he find out about them and how will he react?