Shinichi Kudo and Ran Mouri
Ran Mouri is Shinichi's childhood friend and canonical love interest. They have known each other since as early as kindergarten and had been playmates since then, which caused some censure from Eri Kisaki.They are very close together, they have even been together as long as the time of children all the way to young adults, they have some what of a love hate Relationship in the beinning but when she meets Conan (Which is Shinichi but She doesn't know it) Tells him that She was in love with him for some time probably ever since they first met, which causes shinichi/conan blush like mad. They are living together with her dad and solves crimes with her father (Without her noticing) Making him a great detective for most of the cases that Shinichi has solved himself. He has shared a great deal of affection to Ran since him being Conan including hugging, Holding hands, and even one time slept in the same bed and even took a bath together (Which caused him to get a nose bleed). And while still as conan he is able to keep other guys away from her as seen in episode 6 when tells the guy to never go near her and at the end discover the chocolate that Ran made was for him which she shared with him saying the are celebrating Friendship. Shinichi has confessed to ran in the 4th movie 'capterd in her eye's' so that she can get her memorey back, also he was planing to propose to her but got interupted by a case that got held there. Also when Shinichi went missing Ran was worried sick and she was affraid that something bad has happened to him and almost went to the police, it is also showed that she couldn't even sleep cause she missed him all to much. So what shinichi does is that he uses his bow tie to mimic his real voice and calls her to tell her that everything's alright and all he's doing is getting cases done. Throughout the series they have a romantic relationship that started as childhood friends but develop into true love.