That looks like a copy of what was linked in the original post (or the other one was copied from this), although I didn't compare them word-for-word. Of course this is a link to everyone's favourite IBM site
@ohmylove2u, do you have a floppy for it? That linked page says the 5295-002 starts from a disk, and I see your machine looks like it has a floppy drive.
Also, do you have a keyboard for it?
https://bitsavers.org/pdf/ibm/5250_...its_Product_Attachment_Information_198910.pdf mentions that there are Katakana keyboard(s) for 5250-compatible terminals (which it sounds like this may be). I don't know if
all 5250-compatible terminals for the Japanese market had Katakana keyboards though.
If it is indeed a 5250-compatible terminal (or at least it's partly one), and you can get it to boot up as one with the necessary software, you could potentially build
one of these converters (or ask inmbolmie to build one for you) and try to use it as a VT52-compatible (fairly dumb) terminal. It might require some work to create a key map for a Katakana keyboard unless it's just a superset of one of the non-Katakana keyboards.
I wonder what the "G" means? Some 5250-compatible terminals support graphics apparently, but mine doesn't so I haven't paid much attention to that feature