There is a special 11th berry that you can obtain. This special berry is blue in color instead of red, and will greatly reduce your fatigue in rainy or snowy weather. To obtain this berry, you will need 10 cucumbers. If you've never met Kappa before, then you will need an additional cucumber. For 10 consecutive days, the player must go to the lake surrounding the winter mine and throw a cucumber in. Each day that you do this, Kappa will appear and comment on how persistent you are. If you throw one cucumber in the lake for 10 days straight, Kappa will reward you with the Mysterious Berry on the 10th day and asks that your character leave him alone.