Keshi are little, usually monochromatic, rubbery figurines that are very popular in Japan. You can get them out of capsule machines (“gachapon”), in little packages, boxed sets, as giveaways on events, you name it. Keshi are often tied to popular game or cartoon franchises and, among many other Bomberman sets, there has also been one made a Virtual Boy set with characters from Panic Bomber and the unreleased Virtual Bomberman.
This set consists of reportedly 10 different figurines, each being close to 5cm x 5cm in size and coming in various colours.
More info here.