Soldier Klaus von Wolfstadt becomes a knight to enemy commander Taki Reizen, leading to a strong romantic bond tested by conflicts.

The story takes place in a fictional world that has just begun a great world war. Klaus von Wolfstadt, from one of the nations of the "Western Alliance", has left his duty as a soldier to his nation in order to be a knight to Taki Reizen, commander of the 15th division "Rozen Maiden" whose country has an alliance with "Eurote", an enemy of the Western Alliance. The story follows their romance as it evolves from friendship to love, battling mistrust, doubt and anger before solidifying in an unshakable bond. At every turn their relationship is tried and tested, battered by both enemies abroad and those at home as they struggle with their own feelings for one another.