wait how could you mod this game?
It can be modded using 2dfightermakernd2002
And Hex editor
Also sound and sprite reaper may be useful
Personally i use another game in same platform just to see the code because this game is in japanese
Be sure to keep a backup of the original game as there is a high risk to permanently lost it
If you want to use your sprites or edit existed one you will need an image editor, i use krita or photoshop
The images must be in 16bit color and bmp format
The 2dfightermaker2nd 2002 is very finicky and can crash at any moment or time so backups must be made anytime you replace a sprite or edit the code is a trial and error i used some guides on youtube but rest is from personal experience using the program
The hex editor is important as the original sprites are locked you can see that as in the first line the numbers are ending with the letter "D" if you replece the letter "D" with "K" (be sure to keep a backup file ) you can insert the modded character in the game or any other game that it is mad in this platform
Only you need is patient because it is really time consuming many time i try and quit as errors keep showing up
Anyway have fun if you try modding