Midori Takizawa is the chief technical developer and equipment designer for the secret organization Takeshi in Kamen Rider Hibiki. A brilliant engineer with a doctorate in engineering, she runs the development and experimentation lab located beneath the Tiger Candy Shop, Takeshi's Kanto branch headquarters. Her most significant contributions include creating the Disc Animals—compact, shape‑shifting mechanical scouts used by the Oni for reconnaissance—and developing key weapons such as the Armed Saber and the enhanced Ongekiko Bakuretsu Kaentsuzumi. She also modified Hibiki’s Ongekibo Rekka and invented a specialized Golden Wolf Disc Animal to protect Zanki's injured body during combat.

Midori’s background is closely tied to Hibiki’s own journey. The two were classmates in middle school. After a classmate was forced to transfer due to a bullying incident, a despondent Hibiki was confronted by Midori, who bluntly asked, “And you call yourself a man?” That remark spurred Hibiki to begin training, eventually leading him to become an Oni. Years later, after Hibiki had transferred away, Midori was being harassed by thugs when Hibiki reappeared and let them beat him without fighting back, demonstrating his discipline and resolve. Deeply moved, Midori decided to support the Oni from behind the scenes and joined Takeshi.

Her personality is lively and at times slightly clumsy, with a fondness for sweets that she often eats while working. She is cheerful and approachable, but when discussing the dangers the Oni face, she becomes intensely serious and protective. She dislikes equipment malfunctions because they directly endanger her colleagues. Her scientific curiosity and inventive drive are balanced by a warm, almost motherly concern for the younger members of the team.

Midori serves as the primary tech support for the Kanto Oni, often staying in her underground lab while coordinating with the field agents. Though she does not fight directly, she is a vital part of the organization’s operations, analyzing Makamou patterns, refining gear, and occasionally helping with research into ancient texts. She also acts as an informal big sister figure to the younger characters, especially Asumu Adachi and the Takiwa sisters. She is one of the few people who knows the full details of Hibiki’s past and the reason he chose the path of an Oni.

Her key relationships include a deep, lifelong bond with Hibiki, whose safety she prioritizes in her inventions. She works closely with Ibuki and Todoroki, providing them with the tools they need for battle. She becomes a trusted confidante to Asumu, explaining the nature of Makamou and Oni to him when he first stumbles into the Takeshi world. She also develops a protective affection for Kasumi and Hinaka Takiwa, spending casual time with them outside of work. Her relationship with Zanki is professional but empathetic; she custom‑makes the Golden Wolf disc to ease his chronic injuries.

Midori does not undergo a dramatic personal transformation over the course of the series—she remains a steady, reliable presence—but her role highlights the theme of supporting others in ways that do not require supernatural power. Her dedication to her craft and her quiet bravery in facing the constant threat of the Makamou are notable aspects of her character.

Her notable abilities are purely non‑combat: she is an exceptionally gifted engineer and inventor, highly skilled in electronics, robotics, and materials science. She can reverse‑engineer Oni artifacts, design complex mechanical systems like the Disc Animals, and create weapons that amplify the Oni’s natural abilities. She also has a thorough understanding of Makamou biology and behavior, allowing her to recommend tactical approaches. Although she rarely leaves the lab, she has demonstrated surprising physical agility when necessary, such as using a kick to defend Asumu from a sudden attack.