Heiji is a teenage detective from Osaka and is known as the "Great Detective of the West". He was the first to deduce Conan's secret identity and has since helped him on many cases. He has fun jokingly (sometimes mistakenly) calling Conan "Kudo" in front of Ran at his friend's expense. He often treats Conan/ Shinichi as a younger brother and their close relationship even evokes Kazuha's jealousy from time to time. In return Conan truly trusts and respects Heiji.