Keyboard

Description
A Keyboard is something typically used for writing, but it can double as a deadly weapon on the right hands. It is well known that a true yakuza will only ever use a gamepad, so in this sense, using a keyboard would destroy his status and pride as yakuza, and thus only evil criminals and honorless yakuza dare to wield them as weapons. Thus, Keyboards became the conceptual antithesis of any real yakuza who carries himself with honor.

Season 0
Sonozaki Steven is knocked out and falls ill after being attacked with one, and Kiryu Kazuma & Kasai Tatsuyoshi react in disgust when they figure out there's a monster somewhere using keyboards against them.