The Pen-B System (ペンビーシステム, Penbīshisutemu) is what started off the B-Daman Crossfire franchise in Japan on August 28, 2010, based on the CoroCoro Comic comedy manga series A Penguin's Troubles. As one can expect, the B-Daman boast an obvious penguin motif, in correlation to the manga, in which the main protagonist is an anthropomorphic penguin.
The Pen-B B-Daman toys can also be customized with "Custom Mail", armor pieces with a knight motif. The letters for the product codes of the Pen-B series are BM.
B-Daman in the Pen-B series