For some missions, you need to collect stuff from your neighbors. If you are wondering why your counter in the mission is going down instead of up, than this might be the reason:
- Important: leave the items that you need for the mission in your gift box! As long as you are working on the mission, DO NOT TRADE THEM IN YET！
- Once you have collected enough of the item to meet the requirement in the mission, open up the mission panel.
- In this mission panel, a USE button will have appeared. Click the USE button in the mission panel (not in the gift box!) and your mission is accomplished.
- If you have a number of the item left in your gift box at this point, you can safely trade them in for OP now.