B-Medals (Japanese: Ｂメダル Bī Medaru) are toy-exclusive Yo-kai Medals introduced following the release of the Yo-kai Watch Busters games, with the design of the Yo-kai Medals serving as the standard Medal designs in-game. These Medals work with the DX Yo-kai Watch U and Dream. When B Medals are inserted into either DX Yo-kai Watch models, it performs the normal soundbytes, but it also adds a musical motif, followed by announcing that Yo-kai's role as a Buster.
B Medals are black (except for the Legendaries), with their artwork featuring their Yo-kai doing some sort of action, with the name being written in calligraphic font.
Similar to the Z and U Yo-kai Medals, B Medals feature a distinctive marking in the upper right corner of 4 specific kanji, which vary depending on what that Yo-kai's role is as a Buster: Attack (Japanese: 攻 Kō) for Fighters, Heal (Japanese: 治 Ji) for Healers, Odd (Japanese: 奇 Ki) for Rangers, and Protect (Japanese: 守 Shū) for Tanks. The kanji, much like the names, are written in a calligraphic font. The role of a Yo-kai as a Buster also influences the inner frame's color: Red for Attackers, Green for Healers, Purple for Rangers, and Dark Blue for Tanks.
There are also B Medals that depict Boss Yo-kai. The B Medals that have Boss Yo-kai on them are known as Boss Medals (Japanese: ボスメダル Bosu Medaru). When inserted into the DX Yo-kai Watch U toy, it will play a ominous electric guitar chord.