New Children's Book Series 'Nazotoki Kaitoudan Schloss': Free Riddle-Solving Event Launches at Bookstores! Limited Bookmarks with Short Stories at 13 Miraiya Shoten Locations

Released on April 22, 2026, the first volume of the new riddle-solving children's book series 'Nazotoki Kaitoudan Schloss,' produced by RIDDLER—a group of riddle creators led by Ryogo Matsumaru—is gaining attention as an unprecedented book themed around 'reading,' 'solving,' and 'creating.' This in-store campaign is being held at 13 Miraiya Shoten locations nationwide, including Sendai Uesugi, Natori, Laketown, Kawaguchi, Itabashi, Makuhari Shintoshin, Niigata Minami, Suzaka, Kakamigahara, Hamamatsu Ichino, Suzuka, Shijonawate, and Akashi stores. These stores often feature 'Miraiya no Mori,' a space designed to expand children's curiosity through a wide selection of books, storytelling events, and original artwork exhibitions. Thanks to the cooperation of Miraiya Shoten, visitors can participate in a free riddle-solving experience. A B2-sized riddle poster based on the world of the book is displayed in-store. Participants simply fill out an answer sheet and take it to the register to receive a limited edition bookmark, regardless of whether their answer is correct. The front of the bookmark features 'Phantom Thief R,' while the back features the protagonist, Hayato. By scanning the QR code on the back, readers can access an exclusive short story involving Hayato and the heroine, Chinatsu. Furthermore, special digital signage messages featuring the three main characters will be displayed from April 24 to May 21 at select locations. 'If you don't want your secrets exposed... become a phantom thief.' Schloss is a mysterious phantom thief group causing a stir by setting riddles in school. Chinatsu, an aspiring detective, is determined to catch them. Hayato, her 'assistant,' accidentally becomes a member of Schloss. If Chinatsu finds out, she'll hate him. Hayato must now create riddles as a phantom thief while keeping his secret. 'I started writing this story hoping more children would want to try creating riddles themselves. I've prepared a big surprise at the end. Please enjoy the story with a pencil and paper in hand!' Author: Uro Yamadori. Born in Ishikawa in 1996. Graduate of Tokyo University. Member of RIDDLER Inc. Planning: RIDDLER. Led by Ryogo Matsumaru, aiming to create a world where everyone loves thinking through 'Eureka' experiences.