After the events of the anime, Jin and Lightning go on a trip to Italy...
Read in English on MangaDex | Download | Original Artist
This one was kindly commissioned! I'm actually a YGO fan, but only watched up to Zexal (my favourite one). Despite that, this doujinshi was actually really interesting! I'll have to be a fan of these two now. Here's the artist's Booth (closed at time of posting).
The title of this book, Houseki ni natta Hi, is a song from 2016 with very fitting lyrics, so I believe it is intentional. You can read them in English at LyricsTranslate.
This is probably the longest work I've translated at total of 113 pages. It's a beautifully done work though, I can really feel the author's love of Italy in it. There's even a reference to the Divine Comedy, which as a casual fan of, is pretty cool to see! There's also a small omake that was posted on Twitter, see the translation of it below the cut.

