>>531764676
I'm not going to be helpful but I can tell you it's sure possible to mod 3DS games, an anon made a mod for SMTIV for me once that replaced B2 with this
https://www.youtube.com/watch?v=N4RBz9x3Pzw
If that game is possible then I don't see why DSJ wouldn't be, but may I ask why? I'm 99% sure there are HD music and upscaled art mods for original SJ on the DS
I don't wanna link to leddit but google 'The Ultimate Beginner's 3DS Romhacking Guide!' and it's going to be the first link.