Conan: Starting from Signing the Contract with Haibara Ai

I, Ren Sukawa, am a second-rate detective who is outside the rules of the world. One rainy night, I picked up a little girl from the future, Miyano Shiho. With despair and grief, she tried to reverse a doomed death. Very interesting, isn't it? So, I provided her with a contract - I gave her the opportunity to intervene in her destiny, and she permanently mortgaged her future to me. She signed her name and the mark was engraved.