Soak gelatine in cold water. Peel and roughly dice the persimmon. Place in a tall cup and puree finely with a blender. Mix yoghurt, lemon juice, vanillin sugar and sugar.
Squeeze out the gelatine and melt at low heat. Remove from the heat and slowly stir in 3 tablespoons of yoghurt. Then stir everything into the yoghurt. Chill the yoghurt until it begins to gel.
In the meantime whip the cream until stiff. Fold the cream into the yoghurt in portions. Layer yoghurt mousse and kaki puree in glasses, marble a little with a wooden stick. Decorate with kaki slices and mint leaves.