In a bowl, mix sugar and egg yolks, and stir vigorously, until a smooth cream is obtained. Add mascarpone cheese and stir vigorously. Whip the egg whites until stiff and add them to the cream. Soak the lady fingers in the fruit juice and cover the sides and bottom of a Charlotte mold. Fill the cake mold with a layer of fresh fruit, one of mascarpone cream, one of the soaked lady fingers, and so on. End the cake with a layer of lady fingers. Chill for at least 5 hours. When serving, remove the Charlotte cake from the cake mold and garnish with fresh fruit.