On Sale Today! A completely new children's book born to enjoy through 'Reading, Solving, and Creating'! Vol.1 of 'Mystery-Solving Phantom Thieves Schloss' by RIDDLER Published & Special Website Launched

On Wednesday, April 22, 2026, the first volume of the children's book series 'Mystery-Solving Phantom Thieves Schloss 1: Secret Phantom Thief Debut!', created by the mystery-solving creator group RIDDLER led by Ryogo Matsumaru, was released by Futabasha. Planned as a 'new sensation mystery-solving children's book' where readers can experience not only 'reading' and 'solving' but also the fun of 'creating', this work features a structure where readers can challenge a total of 9 mysteries while following the story. Furthermore, at the end of the book, readers can challenge 'mystery creation' themselves, making it an unprecedented new children's book. On the same day as the release, a linked special website was also launched in conjunction with the book's publication. On this site, in addition to being able to challenge the mysteries that appear in the main story, a mechanism is provided where upon answering correctly, readers can post '#MysterySolvingPhantomThievesSchloss Trial mystery, solved!' on X (formerly Twitter). The design allows the reading experience to be shared on SNS. Furthermore, the pages of the 'Let's try making a mystery' corner included at the end of the book are also available for download, providing a pathway for the readers themselves to step into the role of 'the side that creates mysteries'. In the future, the release of new mystery-solving questions and additional downloadable content is also planned, expanding the enjoyment continuously even after the book's release. ▶ Special Website: https://fr.futabasha.co.jp/special/nazotokikaitoudan/ Bookstore personnel who actually read this work as a trial reading for related parties have voiced opinions such as, 'The fact that you can learn how to make them, not just solve them, is new,' 'A book that expands the ways to play, such as competing with friends or showing off mysteries you made yourself,' and 'I wish I had encountered this when I was in elementary school!' There are also evaluations like, 'It is easy to pick up even for children who are not good at reading,' and 'With a difficulty level that can be solved with a little thought, it seems likely to reach children who like quizzes and riddles,' showing expectations for its potential as an 'entrance to reading.' Furthermore, comments such as, 'The characters are attractive and easy to empathize with,' and 'The illustrations are cute, and the characters feel alive,' were also seen. With all kanji having furigana and numerous illustrations inserted throughout, the ease of reading in terms of the story is also supported. Above all, many voices say that the depiction of the relationship between the protagonist Hayato and the heroine Chinatsu, and the 'secrets' each holds, is likely to evoke empathy from children. Enjoying reading like a game, yet properly using your head. This work presents a 'reading experience that doesn't end just by reading.' The difference from conventional mystery-solving books is that, in addition to the fun of solving mysteries, it touches on the 'creating perspective' of 'how to surprise the other person and make them find it interesting.' Liking mystery-solving and mysteries. Wanting to acquire the 'way of flashing' and 'way of thinking' for mystery-solving. Wanting to experience 'Thinking is fun!'. Being excited by stories of detectives and phantom thieves -- It is a highly recommended book for such children and parents. 'If you don't want your secret revealed, ...become a phantom thief.' Recently, the unidentified phantom thief group has been setting up mysteries in the school and causing a commotion. Chinatsu, a girl who yearns to be a great detective, burned with a strong competitive spirit against their existence. Hayato (the protagonist), a boy acting as Chinatsu's 'assistant', accidentally becomes a member of the phantom thief group one day. If Chinatsu finds out, she will surely hate me --. While harboring a secret that must never be revealed, Hayato ends up creating mysteries as a 'phantom thief'... Secrets, lies, and inspiration intersect in this 'School x Phantom Thief x Mystery Solving' new series, opening here! ■ Comments arrived from the author, Yamadori Amatsuyu!! I started writing this story hoping to slightly increase the number of children who think 'I want to try making a mystery.' I have also prepared an extraordinary surprise for the ending. By all means, with paper and pencil in hand, please enjoy the story! Author: Yamadori Amatsuyu Born in Ishikawa Prefecture in 1996. Graduated from the University of Tokyo and completed graduate school at the same university. Belongs to the mystery-solving creator group RIDDLER Inc. Authored 'Summer Sky Pleiades' (Shogakukan), 'Aim! Nazotore Koshien', and 'Mystery Solving Ink Battle Survival' (both by Fusosha), etc. Winner of the 16th Sogen SF Short Story Award. Planning: RIDDLER A mystery-solving creator group represented by Ryogo Matsumaru. Under the motto of 'creating the best "inspiration experience" and making a world where everyone can love thinking', they are active in a wide range of fields including TV, books, events, regional revitalization, and education businesses. Illustration: Ozido Born in 1999. Illustrator living in Okinawa Prefecture. Mainly creates animations and illustrations with a pop art style. Title: 'Mystery-Solving Phantom Thieves Schloss 1: Secret Phantom Thief Debut!'