Masotan is an Organic Transformed Flyer (OTF), a dragon concealed within the Japan Air Self-Defense Force's Gifu Air Base. He disguises himself as an F-15J fighter jet using specialized transforming armor to avoid public detection. Masotan requires a pilot to guide his flight, swallowing them whole; the pilot directs him from inside his stomach via a natural holographic control system, protected by an acid-resistant suit. He exhibits selective behavior, refusing potential pilots for years until spontaneously choosing Hisone Amakasu. Physically, he possesses large wings, a long tail, and distinctive black sclerae with white irises visible during ingestion or regurgitation. Masotan consumes minor metals, particularly those from outdated electronics like flip phones. Emotionally, he displays loyalty, seriousness, and fear of strangers. Hisone initially nicknamed him "Otofu" (based on "OTF") but discovered his true name, "Masotan," inscribed on a plaque inside his body; this naming holds ritual significance. A prior pilot referred to him as "Oscar." Masotan's bond with Hisone proves exceptionally strong. When she developed romantic feelings for another person—triggering "anastomosis," the OTF's violent rejection of pilots who form human romantic attachments—he initially expelled her. However, their connection enabled a solution: Hisone reconciled her love for Masotan with her human emotions, allowing her to resume piloting. This bond became critical during the Ritual, a cyclical event every 74 years where dragons guide the colossal dragon Mitatsu-sama to a safe location ("the throne") to prevent catastrophic destruction. Traditionally, completing the Ritual required sacrificing a human priestess to Mitatsu-sama. Due to Masotan's unwavering loyalty and unique synchronization with Hisone, she survived acting as the sacrifice, achieving the first successful Ritual completion without a fatal offering. Masotan rejects pilots who emotionally prioritize others, as seen when he abruptly stopped accepting his previous pilot, Moriyama, after she fell in love and became pregnant. His role extends beyond military operations; dragons are regarded as divine beings possessing a key to the world's future, with Masotan's actions directly influencing humanity's fate during the Ritual.