Takemoto Sensei (武本 先生) is the homeroom teacher for Class 1-3 at Kuromata High School and — more relevantly — a secret monitor and special advisor for the Bureau of Anomalous Information Management, tasked with managing the world's first officially designated human-dragon hybrid. He attended college with Umi Aoki, was contacted by her before the school year began to be "filled in" on Ruri's situation, was specifically assigned to Class 1-3 to monitor Ruri's development, and has been covertly managing her biological, legal, and social integration ever since.
His school presentation is that of a "four-eyed slacker" who never breaks 50 percent effort. He eats cup noodles in the career counseling room and calls it "flexing elite privileges." He bribes students with advance study materials to join committees. Yuka Hagiwara calls him a slimeball. He considers himself everyone's favourite teacher. None of this is wrong.
What is also not wrong: he correctly identified Ruri's venom before she did, devised the typhoon-clearing strategy during the Sports Festival, gave Ruri her official Double No. 1 designation, arranged a face-to-face meeting with a pure dragon when her Spurt was running amok, and is the reason none of Ruri's biological incidents have escalated into the global climatic catastrophe they technically could become. He operates at roughly 20 percent visible effort and 100 percent actual competence.
Takemoto is a young man with dark, messy, somewhat curly hair and rectangular-framed glasses. His default expression is relaxed or mildly tired — easygoing as a baseline presentation, not as a specific emotional state. He is almost always depicted with a casual smirk or a look of mild boredom that is functionally indistinguishable from how he looks when he is actively managing a supernatural emergency.
His professional attire is comfortable rather than formal: light-coloured long-sleeved button-down shirts paired with dark ties and knitted sweater vests, appropriate for a teacher who is also apparently a government agent but has decided not to dress like one. During the Sports Festival he switches to casual athletic wear. He eats cup noodles in the career counseling room and describes this as an elite privilege. His appearance is entirely consistent with the role of someone who wants to look like a slacker so that no one asks follow-up questions about what he actually does.
Takemoto's personality is a deliberate performance layered over a genuinely functional set of capabilities. The easygoing teacher is real. The strategic monitor is also real. These are not contradictions — they are two modes of the same person operating in different registers depending on what the situation requires.
The Slacker Facade
He never breaks 50 percent effort in his daily school duties. He uses study material bribes to populate his committees. He refers to eating noodles alone in the career counseling room as flexing his elite privileges. Yuka calls him a slimeball. He finds this very funny. Students like him because he is approachable and low-pressure. This is useful for his actual job, which requires him to be the person Ruri trusts with the sensitive information without triggering the institutional alarm response that a more formal authority figure would produce.
The Monitor
When something biological and alarming happens, he is calm, knowledgeable, and specific. He identified the venom before Ruri understood what had happened. He devised the typhoon strategy. He arranged the Mount Ontake expedition. He knew Ruri's traits and their likely manifestation timeline before the school year started. His assessment of the situation is always ahead of where Ruri and her family are, and his response is calibrated: he reveals what is necessary when it becomes necessary and not before.
Protective Pragmatism
His stated primary motivation is ensuring Ruri can live a safe and peaceful life within human society. The way he pursues this is not protective hovering — it is institutional management. He builds legal frameworks (Double No. 1 designation), deploys cleanup crews when needed, coordinates between the Bureau and the Aoki family, and places himself in the school where he can observe developments in real time. He apologised to Ruri for being reluctant to "throw her into the deep end of the fantastical" before the Spurt made it unavoidable. He was not wrong to be cautious. He was also not wrong to change approaches when the situation changed.
The Awakening — Chapters 1–6
Takemoto's debut established his mode immediately: Ruri arrived with horns, he asked her to explain, and told the class that "breathing a little fire is nothing to make a fuss about." He had been briefed by Umi Aoki before the school year started. The nonchalance was prepared. He used bribes to put Ruri on the Sports Festival Action Committee with Akari Maeda to help her reintegrate — giving her a structured reason to be present with classmates in a setting where she could be useful rather than just an anxiety-producing anomaly.
The Monitor Reveal — Chapters 15–20
When Ruri coughed up venom during a committee meeting and noticed Takemoto identifying it before she understood what it was, she cornered him. He admitted: "I'm here to monitor in a special advisory capacity. But shh! That's a secret." He explained his mission — managing her presence, taking the reins, preventing the world from going up in smoke — with the same casual delivery he uses for everything else. The reveal was significant for Ruri. For Takemoto, it was simply the moment when the maintained separation between his two roles was no longer operationally useful.
The Sports Festival — Chapters 26–32
Takemoto devised the plan to use Ruri's Weather Control trait to clear a typhoon during the festival — walking her through the biological process of building an electrostatic charge and the historical context for why dragons vowed not to use such powers under the Nonaggression Pact. He also guided her through managing her Limit Form. Following the festival, he presented her official classification from the Bureau: Double No. 1 — a legal framework that gave Ruri a defined status within the institution that manages human-dragon relations. He considered offering her No. 0 and settled on No. 1.
The Spurt and Mount Ontake — Chapters 43–47
When Ruri's biological Spurt put her surging energy at risk of running amok — she lacks the regulatory organs pure dragons possess — Takemoto shifted register explicitly: "Know that this advice is coming not from your teacher, but from an expert." He arranged the Mount Ontake expedition, acting on a request from Ruri's father. He revealed to Ruri that he and his organisation had been involved with the Aoki family since her birth. He remained in Nagano to monitor the situation while Ruri climbed to the summit alone.
Ruri Aoki — His Assignment and His Charge
Takemoto was specifically assigned to Class 1-3 to monitor Ruri. The professional relationship is clear: she is the assignment, he is the handler. What develops across the series is more layered than that framework suggests — he genuinely works toward her safety and peace rather than simply her management, apologises when he was wrong to hold back, and shifts from teacher mode to expert mode explicitly when the situation requires it. Ruri initially finds him "sus," eventually trusts his expertise, and regularly tells him to stuff it when he is being annoying about it. Both of these are accurate responses to who he is.
Umi Aoki — College Classmate and Primary Family Contact
They attended college together — which is why Umi was able to contact him directly before the school year started to fill him in on Ruri's situation and assign him as the school's informed first responder. Their coordination is frequent and practical: she communicates through phone and Line to update him on Ruri's condition, he relays Bureau-level information about what to expect next. The relationship is collegial, mutually reliant, and built on shared history that preceded the professional arrangement.
Ruri's Father — The Dragon on the Other End of His Coordination
Takemoto acts on the father's requests — including the Mount Ontake expedition, which was arranged based on information the father communicated through Bureau channels. He serves as the liaison between Ruri's pure-dragon parent and her human institutional life, translating the father's needs and wishes into the specific interventions that serve Ruri's development. The nature of their direct communication has not been fully depicted but the coordination is confirmed as ongoing.
Director Isshin Kyogoku — His Bureau Superior
Kyogoku is Takemoto's superior at the Bureau of Anomalous Information Management. The working relationship is that of a field agent and their director — Takemoto reports up through the Bureau's structure and operates with Kyogoku's institutional backing. The direct dynamics of their relationship have not been explored in detail.
Class 1-3 — The Students Who Think He's a Slacker
He is generally liked by his students, who find him approachable and low-pressure. Yuka Hagiwara calls him a slimeball for the committee bribery. He considers himself everyone's favourite teacher. Both assessments are accurate and neither contradicts the other. His students do not know what he actually does, which is the intended outcome of how he presents himself.
- His first name is not disclosed in the series. He is referred to exclusively as "Takemoto Sensei" or "Mr. Takemoto." His age, birthday, height, and blood type are also not stated.
- He attended college with Umi Aoki — which is the specific pre-existing relationship that made it possible for Umi to contact him directly before the school year started and assign him to Ruri's class as the school's informed first responder. The Bureau placement was not coincidental. He was selected in part because the family contact already existed.
- He eats cup noodles in the career counseling room and describes this as "flexing my elite privileges." This is the series' most concentrated piece of evidence that his slacker presentation is genuinely enjoyed by him rather than merely maintained as cover.
- His name is linked to the Nonaggression Pact — indicating deep ties to the historical framework of human-dragon diplomacy that predates the current story. He is not simply a monitor assigned to a new situation; he is part of an institutional lineage with a longer history than Ruri's specific case.
- He uses midterm study materials as bribes to populate his school committees. He placed Ruri on the Sports Festival Action Committee specifically to help her reintegrate with her class through structured shared activity. The bribe was the delivery mechanism for a deliberate social reintegration strategy. He did not mention this second part to Ruri when he offered the bribe.
- The shift in Chapter 44 — "Know that this advice is coming not from your teacher, but from an expert" — is the series' clearest moment of Takemoto dropping the teacher persona completely. The two roles are maintained carefully throughout the series; this is the one point where he explicitly names the distinction and chooses the other one for what he is about to say.
- He considers himself "everyone's favourite Takemoto Sensei" — a claim he made immediately after Ruri accused him of being suspicious. The timing is a reasonable indication of how much the accusation concerned him.
Dragon Expertise
Takemoto possesses deep, specialist knowledge of draconic biology, the Nine Traits, and the historical context of human-dragon relations — including the Nonaggression Pact and its specific provisions. He correctly identified Ruri's venom before she understood what had happened, recognised Daemonfire harbingers, and tracked the expected trajectory of her biological development with sufficient accuracy to have been briefed on potential events before they occurred. This knowledge is his primary operational tool.
Monitor Authority and Clandestine Management
As a Bureau of Anomalous Information Management special advisor, Takemoto has the authority to: deploy cleanup crews in hazmat suits for supernatural incidents, manage sensitive medical data through Sugano Hospital, establish formal scientific and legal designations (such as Double No. 1), coordinate inter-species negotiations, and access the historical record associated with the Nonaggression Pact. He is the institutional layer between Ruri's personal situation and the broader systems that could handle it less carefully if he were not present.
Strategic Teaching
He can integrate supernatural anomalies into existing school protocols — using standard institutional frameworks (Provisional Grade Council Rules, committee structures, official designations) to accommodate Ruri's situation within the school's existing operational logic. This prevents the need for exceptional measures that would draw attention or require explanation to broader institutional stakeholders.
Inter-Species Liaison
He communicates directly with pure dragons and with Ruri's father to coordinate hybrid safety — acting as a proxy for the father's requests and as the Bureau's representative in negotiations that involve actual world-busting entities. He does this with the same apparently casual manner he applies to everything else.