New release information A light-hearted remark leads to disaster! The story “From the Day I Pretended to Know It All” by Kasai Mari and Otona Chiaki is now on sale!

[New Release Information] A lighthearted remark can turn into a big deal! Kasai Mari and Otona Chiaki’s story “The Day I Pretended to Know It All” is now on sale! ​ Image
URL: Iwasaki Shoten Co., Ltd. Press release: October 16, 2025 To Members of the Press [New Release Information] A lighthearted remark can turn into a big deal! Kasai Mari & Otona Chiaki’s story “The Day I Pretended to Know It All” is now on sale! Iwasaki Shoten Co., Ltd. (President and CEO: Keiko Komatsuzaki, Headquarters: Bunkyo-ku, Tokyo) will distribute “From the Day I Pretended to Know Everything” (written by Mari Kasai, illustrated by Chiaki Otonai) on October 16, 2025.
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Kasai Mari & Otona Chiaki bring you a story of friendship and the future connected by dance Fuuko, a fourth-grader, has moved from Tokyo to Hokkaido. She lives in a small town by a lake and has only one elementary school. Eager to make friends, Kaze accidentally tells her classmates that she’s met a celebrity. She doesn’t want everyone to dislike her, or think she’s a liar. However, when she finds out that the celebrity will be coming to her elementary school for a shoot, she rushes to do something about it.
https://prcdn.freetls.fastly.net/release_image/35751/407/35751-407-c82004d3bf6dc38ba6850778ca28dad4-1500×1064.jpg Main text
https://prcdn.freetls.fastly.net/release_image/35751/407/35751-407-f776d5d8ae7f3413d0f55949a45f643e-1500×1064.jpg Main text After transferring to a new school, she was hoping to somehow improve her relationships with her friends, but a simple remark caused a big problem! However, the dance they did in Tokyo and Fuko’s actions create a wonderful opportunity. This “it doesn’t matter” duo brings you a heartwarming story that will make readers smile. ●Bibliographic information
https://prcdn.freetls.fastly.net/release_image/35751/407/35751-407-4d61911f6ce80ba824805b6447cf0e6b-1500×2147.jpg Cover Title: From the Day I Pretended to Know Everything Author: Written by Kasai Mari Artist: Illustrated by Otonaichi Chiaki Publisher: Iwasaki Shoten Co., Ltd. Price: ¥1,430 (¥1,300 tax) Format: A5 Number of pages: 112 ISBN 978-4-265-84066-3 Iwasaki Shoten product page: https://www.iwasakishoten.co.jp/book/b10145079.html Product introduction video: https://www.youtube.com/shorts/4wlEGAkph1s *Release dates may vary by store depending on product availability. Sales locations: Bookstores nationwide, online bookstores, etc. ● “A Girl Who Doesn’t Care Either Way”
https://prcdn.freetls.fastly.net/release_image/35751/407/35751-407-e5b2ca7983ea5167b766129653a55bfc-678×965.jpg Cover Title: A Girl Who Doesn’t Care Author: Written by Kasai Mari Artist: Otonaichi Aki, Illustration Publisher: Iwasaki Shoten Co., Ltd. Price: ¥1,320 (¥1,200 tax) Format: A5 size Number of pages: 108 pages ISBN 978-4-265-07267-5 Iwasaki Shoten product page
https://www.iwasakishoten.co.jp/book/b583256.html ●Author profile Kasai Mari Born in Hokkaido. She continues to create stories that carefully express the emotional turmoil of children, and gives lectures and readings throughout the country. Her works include the “Little Bear Cook Story” series (KADOKAWA), “Kikuchi Candy Store” (Alice-kan), “Goodbye Cookie and Me, See You Later” (Hisakata Child), “When the Crayon Broke” (Kumon Publishing), “A Child Who Doesn’t Care” (Iwasaki Shoten), and “How I Feel on That Day” (Kin no Hoshisha), among many others. She is a member of the Japan Children’s Writers Association and the Japan Children’s Book Artists Association. Official homepage http://kasaimari.com/ Otonai Chiaki Lives in Tokyo. Illustrator. Her major illustrations include the “Toni Asobi” series (Komine Shoten), “Bitter Step” (Poplar Publishing), “Sorry!” (Kumon Publishing), “Our Mountain School” (PHP Institute), “See You, For Sure” and “It Doesn’t Matter Either Way” (both Iwasaki Shoten), and “Blue Sea Spaceport” (Hayakawa Publishing).