Butterflies are items needed for the mini-game available during the event Beautiful Sakura Bloom. In total there are 4 types of butterflies:
1. Aerial Butterfly clears one layer of a blocked tile in the mini-game.
2. Sparking Butterfly clears one layer of all blocked tiles in a row.
3. Fiery Butterfly clears one layer of blocked tiles around the tile it was activated on.
4. Firefly—a butterfly that makes invisible tiles with rewards visible.
Note that butterflies cannot clear the blockers.