I just thought of a way Shinichi could tell Ran without revealing to her that he is actually Conan. Note: this will only work if Conan turns back into Shinichi and the BO is defeated. He could tell Ran that he was looking for the BO, and that Conan's parents were helping him. That's why Conan goes home when Shinichi comes back, because the BO has been defeated so his parents can take care of him again. What do you think?