Incidentally, Becky and I just visited Matsuyama for the first time a bit over a week ago, so I was surprised (and delighted!) when RubyKaigi's head organizer Akira Matsuda announced that next year's event will be held in Matsuyama from April 16-18, 2025.
If you've never been, Matsuyama resides in Ehime prefecture, which is on the island of Shikoku, just southwest of Japan's main island. It has one of the most cherished castles in the country atop a mountain at the center of the city and which is accessible by a continuously running cable car. It's also home to Dōgo onsen, which is considered to be the oldest hot springs bath in the country (and one of several inspirations for Studio Ghibli's Spirited Away). Additionally, it's famous for its massive and varied mikan (Japanese clementine oranges) crop—Becky and I got to sample a smattering of varieties from a store that had dozens of local citrus juices on tap, via cute little faucets.
Getting to Matsuyama isn't so bad either. From Osaka, it's about 3.5 hours by train, and a special rapid "Shiokaze" train service runs to Matsuyama from Okayama, making it an easy transfer from the Sanyo Shinkansen.
If you've ever wanted to visit a hot springs resort, or get a glimpse of daily life in a more remote Japanese city than the most well-known tourist destinations, I hope I'll see you next year!
[Translator's note: yama means mountain]