qmk-firmware/keyboards/hhkb/keymaps/shela/readme.md

Shela's HHKB Layout

Layer 0: US Layout
Layer 1: Pseudo US Layout
Layer 2: Dvorak Layout
Layer 3: Mouse
Layer 4: Tenkey
Layer 5: HHKB Fn Key
Layer 6: SpaceFN

Pseudo US Layout

On japanese Windows, HHKB Professional 2 US layout model recognized wrongly as JIS layout without changing OS settings.
But, you can use HHKB like a US layout keyboard as it is.