Hana wa Junai ni JunjiruFlower That’s Sacrificed to Pure Love; 花は純愛に殉じる

From Blissful Sin: At the mansion where his father worked as a gardener, young Daniel met Tsubaki, who was destined to become a "Hana", an official prostitute that serves only the royalty and nobles. In order to have Tsubaki, Daniel went to England to further his studies, and eventually won the highest accolates for a gardener. Coming back to his motherland, Alexxa, after fifteen long years to receive his peerage, he finds that...