Most of the designers have a free group gift at their gacha spots as well - the group is free to join and the gifts are easy to spot in their cute little giftboxes. There is also the Seed of Inspiration for those of you who are true gacha fanatics - if you play the gacha enough times (20 pulls on the same gacha), you get it as a free bonus gift just for playing. These SOI items are usually coordinated to go with the gacha items as special pieces of the sets. Additionally, you might be lucky enough to be there when a Gacha Fairy makes an appearance, bestowing special items on random players.
There is a gacha trade group associated with the event as well for swapping extras and there is also a gacha resale store where you can find many items from both present and past events.
Official Blog: The Gacha Garden
Dates: February, 2018
Start/Location: Gimme Gacha Productions sim