The c571.jp website now shows the 2025 scheduled dates of the SL Yamaguchi operation from May through September.
Google Translate: "This is the operation schedule for 2025. The dates with a colored background are operation days. *Operation dates after October 2025 will be announced as soon as they are decided. *All locomotives are scheduled to be D51."
Kato's SL Yamaguchi is one of my favorite models, and I hope to ride the actual SL on May 24th! If you plan to be there, let me know!