Yes, I unpacked ROM. There are at least 2 files with the same structure in the data/fonts folder: alpha and talk.
First one responsible for system messages and menu and second one for dialogs between characters.
As far as I understand file structure:
[Header Section]
[Data Section]
Header section:
4 bytes: Total file length
4 bytes: Offset in Data section of some table (Table1)
4 bytes: length of Table1
20 bytes: Unknown (padding?)
Table1 contains two sets of pointers (4 bytes each).
First half of table:
offset in the data section of pointer to glyph attributes record
Second half of table - unknown pointers.
Glyph record is:
2 bytes: Code of symbol (I do not determine code page, but probably ShiftJIS)
2 bytes: width of symbol
4 bytes: unknown (seems to to be a pointer in data section for glyph image)
4 bytes: unknown (always 0, padding?)
That's all so far that I found.
Update: bytes from 4 to 7 in glyph record is definetly a pointer in data section to Glyph image. And image seems to be not raster, but some vector format.