The main points in which Ran-kun's world deviates from canon are as follows:
- Ran's a boy. Duh. (He requests that you please get over that.)
- He knows that Conan = Shinichi.
- He is not romantically interested in Shinichi in any way, shape, or form, as he will vehemently insist. Instead he's (admittedly rather cluelessly) interested in Sonoko.
- There is no Sleeping Kogoro. Instead of the sleep darts, Conan communicates with Ran via a small transistor cooked up by Agasa, and with his guidance Ran acts as the front for solving cases. (Thanks to his newfound fame from his 'deductions', and with some organization from Sonoko, Ran now also has his own fan club, which continues to make him flail.)
- Similarly to Conan's tracking glasses, Ran has a modified pager that allows him to track the Shounen Tantei badges within a limited range. He also has a watch flashlight.
- Ran and Conan have devised a number of 'child-like' codes (such as paper airplanes folded a certain way or sidewalk chalk doodles) for leaving each other notes and directions when they have to.
- Princess Mira is instead Prince Mira. (We'll let you use your imagination as to how the rest of that worked out.)
- Heiji Hattori is a girl, and does not know that Conan = Shinichi. She's highly suspicious of Ran, given that his latent 'deducting powers' emerged immediately after Shinichi disappeared, and cross-examines him and Conan at every given opportunity. Ran occasionally thinks that she's terrifying.
- Shinichi has a swiftly developing crush on Hattori, which seems to be reciprocated.
All other events and characters take place the same as they do in canon, with slight changes in details to accommodate the aforementioned facts.