A collaboration between the anime “Nintama Rantarō” and hot spring towns, titled “Ninjutsu Academy: A Relaxing Hot Spring Trip,” will be held sequentially starting November 13, 2026, at Atami Onsen in Shizuoka Prefecture and Noboribetsu Onsen in Hokkaido. Eight types of original merchandise, including acrylic stands and pin badges featuring newly drawn artwork of the characters in yukata, will be available. Pre-orders will be accepted from 6:00 PM on Friday, September 11, through 11:59 PM on Wednesday, September 23 (a national holiday).