Seems related to [[Silky]], which is probably misnamed.

{{{#!highlight c++
// Dumper for Fortissimo EXS's script

#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>

bool is_jis_surrogate(uint8_t c)
{
    if(c >= 0x80 and c <= 0xA0) return true;
    if(c >= 0xE0) return true;
    return false;
}

bool silent = false;
bool debug = false;

void output(int c)
{
   if (!silent) printf("%c", c);
}

void print_string(FILE * f)
{
    if (!silent and debug) printf("printing from %X\n", ftell(f));
    int c = fgetc(f);
    while(c > 0 and c < 0x100)
    {
        c = (c+0x20)%0x100;
        if(is_jis_surrogate(c))
        {
            if (!silent) output(c);
            c = fgetc(f);
            if(c == 0) break;
            output((c+0x20)%0x100);
        }
        else
        {
            if(c == 0x0A)
            {
                //output(c);
            }
            else
            {
                if (!silent) output(c);
            }
        }
        c = fgetc(f);
    }
    if (!silent) puts("");
}

#define eat_string() \
{ \
    c = fgetc(f); \
    while(c > 0) \
        c = fgetc(f); \
}

int main(int argc, char ** argv)
{
    // feed .MES files
    for(int i = 1; i < argc; i++)
    {
        auto f = fopen(argv[i], "rb");
        
        if(!f) return puts("failed to open"), 0;
        
        if (debug) printf("reading %s\n", argv[i]);
        
        uint32_t numlines;
        fread(&numlines, 4, 1, f);
        
        uint32_t startpoint = numlines*4;
        
        fseek(f, startpoint, SEEK_CUR);
        
        if (debug) printf("startpoint 0x%X\n", startpoint);
        
        uint8_t last_command = 0;
        uint32_t last_command_location = 0;
        
        int c = 0;
        while(1)
        {
            c = fgetc(f);
            if(c < 0) break;
            
            // Opcode handling to stay in sync. Not proper reverse engineering, 95% guesswork.
            switch(c)
            {
            case 0x6B: // like a scene header of some sort
                last_command = c;
                last_command_location = ftell(f)-1;
                
                fseek(f, 1, SEEK_CUR);
                continue;
            case 0x00:
            case 0x02:
            case 0x03:
            case 0x04:
            case 0x05:
            case 0x07:
            case 0x08:
            case 0x09:
            case 0x0A:
            case 0x0B:
            case 0x0D:
            case 0x0E:
            case 0x0F:
            case 0x11:
            case 0x12:
            case 0x13:
            case 0x14:
            case 0x15:
            case 0x16:
            case 0x17:
            case 0x19:
            case 0x1A:
            case 0x1B:
            case 0x1C:
            case 0x1E:
            case 0x21:
            case 0x22:
            case 0x26: // ????
                last_command = c;
                last_command_location = ftell(f)-1;
                
                fseek(f, 2, SEEK_CUR);
                continue;
            case 0x51: // ?
            case 0x52: // ?
            case 0x53: // ?
            case 0x54: // ?
            case 0x55: // ?
            case 0x56: // ? (related to 3F and 40?)
            case 0x57: // ?
            case 0x58: // ?
            case 0x5D: // ?
            case 0x5E: // ?
            case 0x5F: // ?
            case 0x60: // ?
            case 0x61: // ?
            case 0x62: // ?
            case 0x64: // ?
            case 0x66: // ?
            case 0x67: // ?
            case 0x68: // ?
                last_command = c;
                last_command_location = ftell(f)-1;
                
                fseek(f, 8, SEEK_CUR);
                continue;
            case 0x30: // stack related?
            case 0x31: // ? (system\stat_chip06)
            case 0x32: // ? (system\gotitle)
            case 0x33: // ? (system\cgpage01)
            case 0x35: // ? (SCEAN_START) (SCEAN_NEXT1) ("00") (advmenu_start)
            case 0x36: // voice related
            case 0x37: // (return_sub)
            case 0x38: // play movie? (movie\ff_op_fripside.mpg)
            case 0x3A: // ? (SCEAN_NEXT1) (return_txt) (CloseMes)
            case 0x3B: // ? (advmenu_start)
            case 0x3C: // ? ("logo_end0")
            case 0x3F: // ? (SCEAN_END)
            case 0x40: // ? (SCEAN_START)
            case 0x43: // ? (@tスキップしますか？)
            case 0x44: // ? ("00") ("01")
            case 0x45: // ? ("最初からシーンを再生")
            case 0x47: // voice related
            case 0x48: // voice related
            case 0x49: // ? (music_play_end)
            case 0x4B: // ? ("1.00")
                last_command = c;
                last_command_location = ftell(f)-1;
                
                eat_string();
                continue;
            case 0x2A: // ? (system\messwin)
            case 0x2B: // music related
            case 0x2D: // ? (advmenu)
            case 0x2C: // music related
            case 0x2E: // related to end of scene file
                last_command = c;
                last_command_location = ftell(f)-1;
                
                fseek(f, 1, SEEK_CUR); // slot?
                eat_string();
                continue;
            case 0x4D: // ? (speaker name?)
            case 0x4E: // "normal" text
            case 0x4F: // choice
                last_command = c;
                last_command_location = ftell(f)-1;
                
                if(c != 0x4D)
                    print_string(f);
                else
                    eat_string();
                continue;
            }
            if(c < 0)
                break;
            
            printf("Unknown command %02X at %08X in %s\n", uint8_t(c), ftell(f)-1, argv[i]);
            printf("Next byte is %02X\n", fgetc(f));
            printf("Last command was %02X at %08X\n", last_command, last_command_location);
            exit(0);
        }
        fclose(f);
        if (!silent) puts("");
    }
}
}}}