Kaguya Kazuha is a central character and can be described through the following key traits and background details:
The Medical Genius: Kaguya is the youngest brother in the Kazuha family and serves as the medical mastermind of the Kazuha Syndicate. He operates as the Head of Dian General Hospital. In the new world, his vital contributions include synthesizing botanical antibiotics, creating advanced triage systems, and developing a new analgesic. Because of these massive societal contributions, he was officially elevated to the rank of Viscount alongside his elder brother Inori. He works together with his eldest brother Takuya
Clinical and Highly Logical: Kaguya operates with a highly analytical, clinical, and pragmatic mindset. Even during deeply emotional or chaotic moments, he defaults to cold scientific reasoning. For example, he chose lilies for his mother's memorial not merely out of sentimentality, but because "structurally, their petals hold up best" in Tokyo's humidity.
Unfazed by Trauma: When the brothers were unexpectedly transported to a terrifying alien jungle, Kaguya completely ignored the panic. Instead, he immediately used a titanium scalpel to dissect the local flora. By analyzing the atmospheric composition, un-oxidized iron, and high oxygen saturation, he clinically deduced they were no longer on Earth while his brothers were still in denial.
Meticulous and Sterile: He is obsessively clean and highly concerned with sterility. He is frequently seen using antibacterial wipes or clean handkerchiefs. His private laboratory is impeccably clean, smelling sharply of distilled alcohol, sterilized linen, and lye, which serves as a stark contrast to his brother Inori's chaotic workspace.
Relationships and Demeanor: Kaguya is betrothed to Princess Aurelia (Aura). She works alongside him as a medical professional on the bloody front lines of his hospital. Overall, Kaguya possesses a calm demeanor, often responding to massive legal victories with stiff, formal nods rather than emotional celebrations, as he focuses on securing the biological future of the Syndicate.