Heiji Hattori, Osaka’s acclaimed high school detective known as the “Great Detective of the West,” is the son of Osaka Police Superintendent Heizo Hattori and Shizuka Hattori. His early fascination with sleuthing began with solving local mysteries like finding lost pets. A defining childhood moment involved being accidentally handcuffed to childhood friend Kazuha Toyama without a key, an ordeal that deepened their bond and led them to craft matching good-luck charms from the cuffs’ links—charms they still wear. In the *Osaka Okonomiyaki Odyssey* OVA, Heiji partners with Conan Edogawa and Kazuha to investigate a woman’s temporary entrustment of her infant. Their discovery of inconsistencies in the baby’s gender clues unravels a kidnapping plot tied to *The Tale of Genji*. The OVA mirrors *24*’s real-time narrative, complete with a digital clock motif and Heiji’s opening line echoing the show’s protagonist. Heiji balances humor with keen deduction, harboring a competitive edge that initially pits him against Shinichi Kudo. After uncovering Conan’s true identity, their rivalry shifts to collaboration. His impulsive decisions sometimes clash with detectives like Saguru Hakuba, as he prioritizes saving lives over preserving crime scenes. A proud Osakan, he champions local culture and cuisine, his distinct Kansai dialect thwarting impersonation attempts. Protective of those close to him, Heiji shields Kazuha from danger during cases and aids Conan in concealing his identity, though he teasingly skirts exposure at times. Their trust culminates in Heiji disguising himself as Shinichi to safeguard Conan’s secret. Beyond the OVA, recurring nightmares of Conan’s demise prompt him to lend his charm—later pivotal in saving Conan’s life. Unspoken romantic tension with Kazuha lingers, with hints of mutual feelings and a film revelation naming her as his first love. Heiji’s investigative ethos stresses teamwork and moral duty, exemplified by preventing a culprit’s suicide to uphold justice over mere puzzle-solving. His evolution from rival to trusted ally underscores a blend of wit, regional pride, and unwavering commitment to protecting others.