Everytime i see a shop item one or two say some qi is required

qi is the amount of matches youve played

qi = experience

15 000qi = 15 000 matches

Velve has it right. You should also know that even if you lose, you still get Qi.
Also, if you're lame you can buy a Qi booster or just buy it directly to get to 10th dan with the experience of a yellow belt.