Ijitte Princess ~Mou! Mata Konna Tokoro de~

Al is the prince of a new kingdom that has quickly risen to become the world’s most powerful nation. To quell the fears of neighboring rivals, and prevent the possibility of them uniting against a common threat, the King has commanded Al to marry a Princess in the name of goodwill. To this end, royalty around the world have sent their most beautiful daughters to broker lasting peace and usher forth a new noble lineage.

[From an old review by Nargrakhan]