The word "capsule" (カプセル, kapuseru) is pretty established in Japan. There are capsule toy machines (also often called "gashapon" or "gacha" but those are respec

The word "capsule" (カプセル, kapuseru) is pretty established in Japan. There are capsule toy machines (also often called "gashapon" or "gacha" but those are respectively Bandai/Tomy trademarks). As another commenter pointed out there are capsule hotels; the working name for Pokémon was originally "Capsule Monsters".