Winning Japan has provided the following suggestions regarding care and storage of their equipment:
Dry equipment thoroughly after use to eliminate excess moisture. Use a dry soft cloth to wipe down your equipment after training. Please refrain from using abrasive materials to clean your equipment. Occasional use of petroleum solvent to condition the leather is appropriate.
Do not soak or dip your equipment in water as this can cause discoloration and deterioration of the materials. If necessary, clean using a cloth dampened with water and dry promptly.
Carefully store equipment by avoiding direct sunlight and humid conditions. Direct sunlight or excess heat can cause deformation or alteration of materials. High humidity can promote bacteria and mold growth. Chose a well-ventilated and shaded area to air out and store your equipment. For these reasons, the car or gym bag are not ideal storage places for your Winning equipment, please avoid it when possible.