Test the tension by opening and closing your scissors carefully. When the tension is set properly, the blades of the scissors should close gently, not fall shut, hardly any pressure is needed in cutting to close the scissors.
All Ninja Scissors have special adjustable screw systems for fine adjustment of the tension. Using the adjusting tool provided with your scissors, turn the screw clockwise to tighten the tension or counter-clockwise to loosen it. Then check again for correct tension.