Initially sold for ¥39,000
Main keyboard to be used with the YIS ecosystem. It attaches to the central PU1 via a (very fragile-looking) ribbon cable. There's a volume control on the back, with a piezoelectric speaker hidden under the top left corner of the keyboard. It's entirely made of plastic, with woodgrain sides to match the wooden cabinet of the GM1 CRT display in its case.
A KB2 model was also available, with chiclet style switches. Overall, the keyboard layout is not very different from the one found on the CX5F.