Gem

General Info
This currency is used for Refreshing certain aspects of the game (Secret Shop, Exploration, etc.) and is used to for Basic, Event, and Seduce Item Summons.

Where to Obtain

 * Shop - Gem Shop and Package Shop
 * Events - Daily Mail (usually)
 * Arena - Daily and weekly rank rewards
 * Achievements - Certain achievements give gems as rewards
 * Story Missions - Completion of star requirement the first time for each mission; The 3rd box in the lower right corner from getting all of the stars in that Chapter.
 * BONUS - Special Deals, Rank Up Reward, Monthly Card, Growth Package