I want to make it clear that I don't have any plans of making my own GiFTPiA translation patch. I have very little experience in hacking GameCube games and my understanding of the Japanese language is still very limited, so I am definitely not the guy for the job (as of now, at least).
That said, I noticed the user MarkAss (who had worked on the Captain Rainbow ENG fan translation) was working on a GiFTPiA translation patch on the side. You can find the thread in question here (https://www.romhacking.net/forum/index.php?topic=24878.0). Here they provided a link containing tools and modified files regarding this unfinished translation, but the download link (https://ufile.io/6cptp) only redirects to a "File Removed" page now. The Wayback Machine has an archive of the download page (https://web.archive.org/web/20180819131817/https://uploadfiles.io/6cptp), but the files in the download are inaccessible. This does show however that the file was titled Giftpia_ENG_Base.rar and was 264.9 MB.
Since MarkAss's account seems to be abandoned, I'm making this thread in the hopes that someone could reupload what MarkAss had completed. It'd likely be helpful to anyone who wants to try their hand at continuing the patch's development. Any help would be greatly appreciated. Thank you everyone.