Hideki Ide serves as a Japanese Task Force member investigating Kira. He has short black hair, light-colored eyes, and consistently wears a green blazer over a white shirt with a red tie. His appearance lacks visible eyebrows. Ide exhibits an impatient temperament, particularly toward perceived foolishness in colleagues like Touta Matsuda. He shares a close, trusting bond with fellow investigator Shuichi Aizawa. This trust drives their joint resignation from the Kira Investigation Team due to Ide's profound distrust of L's secrecy and methods, despite the risks of departure. They pursue an independent parallel investigation to reclaim professional pride. During the Yotsuba Group incident, after Kyosuke Higuchi is exposed as Yotsuba Kira and gains Shinigami Eyes, Ide and Aizawa defy orders to intercept him. They execute a tactical operation using tinted-window police vehicles and specialized helmets to conceal identities, capturing Higuchi while mitigating Death Note risks. This demonstrates their sustained off-the-books preparedness. Following L's death and Light Yagami's assumption of the L identity, Ide rejoins the Task Force full-time. Amid subsequent investigations led by Near and involving Mello, he aligns with Aizawa, providing cover as suspicions mount within the team about Light potentially being Kira. Ide operates under Light’s leadership during this phase. One year after Light's exposure as Kira and death, Ide discusses events with Matsuda. He expresses conviction that ending Kira’s reign was necessary regardless of methods, believing continued inaction would have killed all Kira’s opponents. In other media, such as *Death Note: The Musical*, Ide remains a Task Force member. He participates in resigning after FBI agent deaths during "Change the World Reprise" and leaves the investigation within that narrative. He is absent from the live-action film series as the only core Task Force member not featured.