Aisuru Hito no Kioku: Eien wo Chikau Greece

Return to the wonderful world of Speros Island, and meet the newly wedded Alexei and Bliss "Billie" Drakos. Within hours, their marriage hits a big storm when Billie confesses to Alexei that her nephew, Nikolos, is actually her-and Alexei's-son from a night of unforgettable passion. Except Alexei doesn't remember... He fell down the stairs, hit his head and developed amnesia! Will Alexei accept Niko as his own, or will he run to the arms of the conniving Calisto? Billie is determined to steer the course of this stormy Greek marriage... (Source: MangaPlaza)