Hey there even though I don't play video games, I converted every episode/OVA/MOVIE/Jump Festa/Collab of Gintama to .gba so I can watch them on my GBM anytime, anywhere, no internet!
Here's how I did it, steps with examples down below! Click on the images to enlarge them! Email me if you have any questions about the process.
1. Though I've used alternate methods in the past, for this project I'm using this crunchy downloader which burns hardsubs into the desired .mp4 file.
2. To ensure I get the highest quality, I divy up the episode into three 7-minute parts and export as .mp4
3. I then convert the mp4 files into avi, must be done using this converter specifically
4. Next I use this program to convert the avi to gba
5. After the files have finished converting, I drag to gbafix before dropping them into the microsd cards for my GBA Flashcart
6. HERE'S THE FINAL RESULT!!!