On the continent of Vester, Iso—Supreme Ruler of the Hidden Dragon Dominion—goes into hiding under a humble identity to investigate his mother Saintess Esara's murder. Disguised as an ordinary man, he takes residence in Silvermoon Castle and, honoring an old betrothal, becomes the fiancé of Sera, heiress to the saintess lineage. Sera, however, is obsessed with the legendary Dragon Lord—a mythical figure she has worshipped from afar—and feels only disappointment toward her unremarkable-looking betrothed. She frequently mocks and belittles him, unaware of his true identity. Cardinal Taren of the Orthodox Church, coveting the saintess's power, secretly hires eight renowned Dragon Slayers and rallies noble conspirators to ambush and assassinate Sera time and again. Each time, Iso secretly intervenes, wielding his silver-dragon might to save her. At Dragon Ridge Altar, he finally reveals his true form as the Dragon Lord—yet Sera fails to recognize him. The perils continue: a tavern trap, a royal council coup, and a siege by dark Dragon Slayers—all quietly thwarted by Iso from the shadows. At the climactic final banquet, the Church launches its all-out assault. Iso summons a thousand dragons before the entire assembly, shattering the enemy's ranks. Only then does Sera realize that the "ordinary" fiancé who stood by her all along is the Dragon Lord she so longed to meet. Together, they join forces to counter the Church's conspiracy and uncover the truth behind the past.