Gacha Capsules (or Gashapon, Gachapon, Gatcha, Gacha Gacha, etc.) are popular Japanese capsule toys that include random figures, pins, buttons and collectibles. Typically found all throughout cities in vending machines, customers can buy a random toy for a few bucks (or a few hundred Yen). Collecting them is super fun and there are so many to choose from!
Otaku Boxes sells both random Gacha Capsules, Individual Figures as well as Complete Collections. Whichever you choose is up to you ^_^.