After a rebellion kills his father and leaves the Kingdom of Hortensia in ruins, Alfred Ober inherits his father's sword and vows to become a knight who can protect what's left of his home. Training under the veteran Maurice Baudelaire, Alfred forms a bond with fellow trainee Marius Casterede, whose past hides more than it first appears. This manga adapts the Hortensia Saga mobile game, which also has a separate TV anime adaptation.