There is the ways to get gems
Weekly Missions: 70 gems
-Login 4 times
-Sell 10 items
-Draw gacha 10 times (gold gacha count)
-Send friend points 5 times
-Do daily quest 10 times
-Obtain 20 items from quests
Milestones (recommended to do taks for max gems btw, below listed those who give you gems)
-Complete X main quest chapter on X difficulty
-Complete All special Mode X times
-Complete All Time Attack X times.
-Advance X Character to X Star
-Achieve Supporter/Weapon level 60 X times
-Achieve Supporter intimacy lvl 3 x times.
-Acquire X UR weapons/supporters.
-Acquire X Costumes.
-Acquire X quantity of gold.
-Mega success weapon/support enhancement X times. (easy to get)
-Enhance weapon/support skill x Times.
-Complete weekly mission X times.
This is the best way to get gems every supporter at lvl. 5 of intimacy give you a total of 50 gems, the game have 29 supporters so potentially there are 1450 gems to farm. (to claim the gems go to Collections tab)
Remember to put supporter in the facilities to level intimacy.
Golden pass give 50 gems and invaluable tickets.
Special mode give you 3 gems every 6 hours
Events give Supporters worth of 50 gems and 10 gems for every section cleared and some gems, potentially every event give you 220~ gems.
Every section cleared give you 10 gems so if you clear the 5 chapter in all difficulty there are 750 gems in total.
Per week you can get 154 gems if perfect timed special mode + weekly missions.
By completing supporters intimacy levels and main quests sections challenges you can get 2200 gems.
By Milestones 800 gems just by complete every task I think. For milestone don’t have the number but let’s say 500 gems.
Login bonus don’t give gems usually but give invaluable tickets (UR weapon tickets are valued in 3800 gems seeing the gacha, UR supporters spoke you often because most rates are like 1% UR weapon-2% UR Support)