A friend of mine has a Macway keyboard, I've mashed on it super briefly a handful of times. They're very good. Especially if you're using JIS input, which, say, the Apple IIgs keyboard isn't equipped for in the same way.
That said - F Keys are only useful on Classic Macs if you either want yet another shortcut launcher or have software that uses it, or can have additional shortcuts programmed. I'm sure there is software that allows this, but I don't happen to know of it off hand.
My guess is that the software on the disk either does the same thing the later Apple keyboard panel does, or allows reassigning keyboard shortcuts and/or macros in general, perhaps, say, allowing you to map Command+S to "F7" or whatever one you prefer for a quick save button.
It would, of course, be nice to see.for sure.
Given that the software is likely Japanese made by a Japanese company shipped with a Japanese version of that type of keyboard (variants shipped in the US aimed at children), have you considered looking at the Japanese vintage Mac Internet?