In a school in northeastern Japan, five friends in the animation club, Aoi, Ema, Shizuka, Misa, and Midori swear to complete a new anime called "Shinbutsu Konkou SHICHIFUKUJIN" with some donuts. Since then, day after day, the five spend all of their time on anime production. The awe of going from rough sketches to animation, and the awkward acting in the after-recording session... The final product was finished at the cultural fair six months later. After they graduated they still pursued animation and swore on some donuts that they would make another anime together.

The war between the Levamme Empire and the Amatsukami Imperium has been raging for years. In the midst of this struggle, the prince of the Levamme Empire declares his love for Juana del Moral and vows to end the war in one year, as part of his marriage proposal. When the Amatsukami catch wind of this, they assault the del Moral residence, targeting Juana's life. As a last-ditch effort to bring the prince his bride, the San Maltilia Airforce employs a mercenary of mixed blood—a bestado—to fly Juana to the prince in secret.

There are gamblers out there who even bet their lives as ante. But to secure the integrity of these life-threatening gambles, a violent and powerful organization by the name of "Kagerou" referees these games as a neutral party. Follow Bak Madarame a.k.a. Usogui (The Lie Eater) as he gambles against maniacal opponents at games—such as Escape the Abandoned Building, Old Maid, and Hangman—to ultimately "out-gamble" and control the neutral organization of Kagerou itself.

The story focuses on the exploits of rivals Reinhard von Lohengramm and Yang Wen-li, as they rise to power and fame in the Galactic Empire and the Free Planets Alliance, respectively.