Prof. Iguchi, known in the original Japanese materials as Dr. Higuchi, is a scientist associated with the Mishima Industry conglomerate in Nuku Nuku DASH. He is a former colleague and professional associate of Natsume Kyuusaku, the inventor who later becomes the guardian of the series' central character. Iguchi is the creator of Nuku Nuku, the all-purpose cat-brain android robot, and he is the one who brings her into the Natsume household. When Nuku Nuku comes under threat, Iguchi turns to his old acquaintance Kyuusaku and asks him to take her in, a request Kyuusaku honors by allowing her to live with his family under the identity of the quiet and capable young woman called Higuchi Atsuko.

Within the setting of the story, Iguchi is an experienced developer who has worked on a range of andro-bots for Mishima Industry, giving him a thorough understanding of the corporation's advanced robotics research. His position becomes complicated once the company begins hunting Nuku Nuku, and his choice to entrust her to someone outside the organization places him at odds with his own employer. He is presented as a scientist who cares about the safety and wellbeing of his creation, prioritizing her protection over corporate loyalty. His bond with Kyuusaku is built on long professional history, and it is this trust that allows him to secure a refuge for Nuku Nuku.

Iguchi's role in the story is largely defined by the events that set the plot in motion: his creation of Nuku Nuku, his decision to hide her from Mishima Industry, and the circumstances of his own disappearance. Publicly, it is said that he died in an unfortunate incident, but the full truth of what happened to him is not as straightforward as it appears, and the mystery surrounding his fate is tied closely to Nuku Nuku's past. Because Nuku Nuku has lost her memories, she does not recall her creator, and the truth of her origin remains hidden for much of the series. Iguchi's key relationships are with Nuku Nuku as her maker, with Natsume Kyuusaku as the colleague he relies on in a crisis, and with Mishima Industry as the corporation whose interests he ultimately acts against. His most notable abilities lie in scientific and engineering skill, particularly the design and construction of highly advanced android robots, most significantly the cat-brain android whose well-being becomes his lasting concern.