In the aftermath of a violent uprising orchestrated by Duke Rugis Camellia, the Kingdom of Hortensia is left in disarray with the royal family wiped out or vanished. Knight Maurice Baudelaire narrowly escapes the chaos following the death of his brother, Fernando Albert, in a werewolf encounter. Carrying his fallen sibling's legacy, Maurice seeks out Albert's son, Alfred Ober, presenting him with his father's sword. Despite his sorrow, Alfred recalls a promise made to his father—to become a knight and safeguard their domain, the Albert Dominion. Guided by Maurice, Alfred sharpens his combat prowess to fulfill his vow. Training alongside him is Marius Casterede, a mysterious youth with an age shrouded in enigma. Meanwhile, Pope Alexi Valdebron issues a decree to locate the missing princess and installs Charlot D'Hortensia as the new monarch. 'Hortensia Saga' unfolds as a narrative of unity and resolve, as Alfred, Marius, and Maurice, aided by allies old and new, strive to illuminate the shadows engulfing Hortensia.