Tetsuo Kanda, a highly skilled but reckless F-4EJ Phantom II pilot at the Japan Air Self-Defense Force's Hyakuri Air Base, has a reputation for pushing his aircraft so hard that every navigator who flies with him ends up hospitalized. At Misawa Air Base, Hiromi Kurihara, a navigator of equal talent and an equally difficult personality, firmly believes that the navigator is the true pilot and the front-seater is merely a puppet. Seeking to curb both men, Hyakuri base commander Ota orders Kurihara transferred to Hyakuri, hoping the two will either improve or destroy each other. After an initial clash of wills and a demonstration of their respective skills in the air, Kanda and Kurihara form an unlikely partnership and become the exclusive crew of the 680 Phantom, a well-worn but beloved F-4EJ that carries the call sign Shinsengumi and sports red checker patterns on its fins.

The story unfolds primarily at Hyakuri, with missions centering on search-and-rescue operations, disaster response, and interactions with base personnel, visiting foreign militaries, and civilians encountered through duty. Unlike a war narrative, the manga emphasizes human drama and camaraderie, drawing on the real-life experience of writer Sho Fumimura, who served in the JASDF. The 680 Phantom itself is a character in the story, weathering multiple incidents including bird strikes and engine fires, and earning a reputation for near-indestructible survivability despite its advancing age. A notable early arc introduces American pilot Joey from the nuclear-powered carrier Summit; after Joey lands at Hyakuri in distress, Kanda pilots the 680 to an unprecedented carrier landing to prove the skill of Japanese pilots, forging a lasting friendship.

Over the course of the series, Kanda and Kurihara become known as the Kankuri combo, respected for their talent even as they continue to test the patience of their superiors. Kurihara is a sharp, sunglasses-wearing strategist, while Kanda is a daredevil who, despite his rough edges, once won a base beauty contest in a Chinese dress. A frequent supporting character is Ota's inquisitive and initially aviation-skeptical daughter, Takako. Several storylines involve encounters with former pilots, including a comrade who lost his nerve after an ejection, and an older mechanic who dreams of seeing the 680 reach Mach 2.6.

In a pivotal narrative arc, the original 680 Phantom is finally retired due to accumulated structural fatigue from Kanda and Kurihara's relentless flying. During its final flight, the aircraft breaks apart over the ocean, but the ejection seats deploy automatically, saving both men. Their partnership continues with subsequent aircraft, each still bearing the 680 tail number. The series concludes with the pair facing disciplinary dismissal, but their legacy is such that even the manufacturer seeks to acquire the legendary machine for study. The manga ultimately portrays two unconventional yet brilliant airmen growing through their shared duty, their bond with a fighter that is always pushed to its limit.