Two Conans -> Ran.
Two Rans -> Detective Boys.
Two Detective Boys -> Haibara
If you are wondering where Kaito/KID is then keep playing! He shows up after you combine more people.
What? You’re all words. Do you even know, that the lives of every passenger are in my hands?! Stop acting so cool! You’re always away during the important times and all you do is call. And there are times when you’re finally here, but disappear unexpectedly. Every time… Always, always, leaving me behind, alone… What do you think I am?!
I… I love you, Shinichi!