Hideo Tanimura is the head of the Cultural Department at the Tozai News newspaper. Throughout the series, he is eventually promoted to the position of editor-in-chief, though he often continues to oversee his former department. As a manager, Tanimura is characterized by his calm, gentlemanly demeanor, which stands in stark contrast to the more volatile personalities of many of his colleagues and superiors. He consistently presents a smiling and composed front, even when his subordinates are causing a commotion.

Tanimura's primary function within the narrative is to serve as a voice of reason and a stabilizing force. While other characters frequently ignite conflicts or hold extreme opinions about food and culture, Tanimura reliably acts as a mediator, attempting to calm disputes and resolve problems. He is notably one of the few individuals who does not create trouble for others, and his sensible perspective is often essential for maintaining order within the chaotic newsroom. When Deputy General Manager Fukui or the protagonist Shiro Yamaoka cause an incident, it is frequently Tanimura who makes excuses on their behalf and works behind the scenes to smooth things over. When Yamaoka has a major fight with the paper's president and resigns in anger, Tanimura is the one who builds a bridge for reconciliation.

Despite his easygoing nature, Tanimura commands significant respect when he chooses to assert himself. His anger, which is extremely rarely displayed, is taken with the utmost seriousness by everyone around him, including the often-headstrong Yamaoka and his colleague Yuko Kurita. In one notable instance involving a cooking competition between the two, Tanimura scolded them harshly for their lack of cooperation, demanding an apology and a plan to fix the situation, which immediately prompted them to reflect on their behavior. Even the president and managing director, who are known for being temperamental, find it difficult to argue against him because he always bases his position on sound reasoning. When a relative of a superior was proposed for a key position, Tanimura openly objected, arguing that such nepotism would devalue the entire project.

Tanimura's background is one of relative affluence, as he is a graduate of Denenchofu Elementary School, a well-known wealthy area in Tokyo. He has a son who is described as a good student and a sensible young man, much like his father. At work, he maintains good relationships with most characters, including the head of the rival Jedo Shimbun's curatorial department, with whom he shares a common-sense rapport. In the early parts of the story, he was presented with a sharper, more formidable presence, including presiding over a rigorous taste test for job applicants where he asked them to distinguish between different types of water and tofu. However, as the series progressed and stronger boss characters were introduced, his role settled into that of a kind, reliable, and somewhat overworked middle manager, tirelessly handling problems from both his troublesome subordinates above and below him. He is not typically the protagonist of a story arc focused on his own conflicts, but his consistent presence is crucial to the series' overall structure. His notable abilities include a refined palate and a discerning palate for quality, as demonstrated in the initial tasting exam he administered.