Probably the only reason why you've decided to play this game.
You farm gifts via Exploration Quests and give enough to reach the max of 100 Intimacy with a character to unlock a character's still. Other ways to receive gifts are through Login Rewards and Event Quests.
Note: Mob characters share intimacy with each other. Alternate variants also share intimacy with their original counterparts.
Do note information below contain spoilers.
For data on how often a character may have appeared on stills, you can refer to Character Apperance.
To check which characters have stills available, refer to Still Availability.
Still#
Unlock Criteria
Availability
1
Reach maximum initimacy.
55/79
2
Rank up character (unimplemented)
0/79
3
Reach max intimacy & own their alternate variant.
14/79
4
Obtain character's secret from events.
13/79
Story Stills
These stills are shown through playing through the story and are available for free. NSFW stills are optional, though some give you no choice to go through them.