Chiba and Hanzo are Brian D's "old school" keyboard and mouse, respectively. Brought to VGHS by Brian upon enrolling there, they were destroyed and tossed in a dumpster by The Law in Episode 2, though subsequently retrieved by Ted at some point and repaired by Ki. Throughout the series many have remarked on the primitiveness of Chiba and Hanzo, and Hanzo, the mouse, has even lived up to its perceived primitiveness, and at one point during a match against Annihilist Hanzo backfires, causing Brian's gun to constantly fire and exhaust all his ammunition. Despite this, Chiba and Hanzo mean a great deal to Brian, as he is distraught when they are destroyed and extremely excited and moved to see them when they are repaired.
The names Chiba and Hanzo are a reference to famous martial artist and actor Sonny Chiba and one of his most memorable roles as sushi chef / sword maker Hattori Hanzo in Quentin Tarantino's bloody revenge epic, Kill Bill.
Chiba, the keyboard is the well known IBM Model M. This is a good and sturdy mechanical keyboard from the 1980s.