Guide to Gathering
From Hello Kitty Online Wiki
Gathering is collecting items from plants in the fields or on a farm. When there is a plant that can be gathered, the cursor will change to an arrow when the mouse is hovered over it. Right-click to gather. Some resources have multiple options which can be performed, i.e., it can be both gathered or chopped. In this case, you will see a small menu.
Choose the icon with the hand pulling the leaves in order to gather. Then your character will start to gather, and a bar will appear over the plant.
The progress bar normally takes about 5 seconds to complete. You can apply buffs to help speed the process. When the bar fills up, the gathering is done and an item (drop) will appear in the inventory. Right-clicking somewhere else, or moving, before the gathering is finished will cancel the gathering.