A family of Microsoft word processing software products for creating web, email, and print documents.
I have no knowledge of the Japanese keyboard but this may help:
Try using the macOS Character Viewer. **** Pressing key combinations reveals what the are assigned to.
However, in Word you also can go to Tools> Customize Keyboard to see what the assignments are.
I believe you may have been speaking with someone from Apple who just didn't know what else to tell you 🙂. The keyboard shortcuts work fine provided all is fully updated:
- Subscript — Shift+Command+➖/▁
- Superscript — Shift+Command+=/✚