Volume 10, the latest installment of the wildly popular manga *My Little Sister Knows* by Mari Kanki—currently serialized in *Weekly Young Magazine* (Kodansha)—will go on sale on December 4, 2026.
To celebrate surpassing 1 million copies in cumulative circulation, a celebratory message from Mari Kagi is now available on the official X account!
／
㊗️「妹は知っている」100万部突破！🎊
＼皆様の応援のおかげで漫画家としての大きな夢を一つ叶えることができました。
いつも本当にありがとうございます！ https://t.co/OeuIGqLgMe pic.twitter.com/GWK0owhPbx— 雁木万里 (@yanuimori) October 6, 2026
Article Navigation
Mari Kanki’s “My Little Sister Knows It”: Synopsis of the Latest Volume 10
The synopsis for Volume 10 of “My Little Sister Knows It” has not yet been announced.
*As of October 15, 2026
When is the release date for Volume 10, the latest volume of Mari Kagi’s “My Little Sister Knows”?
Celebrating over 1 million copies sold! Volume 10 of the addictive sibling comedy “My Little Sister Knows,” featuring a genius postcard artist brother and his idol sister, goes on sale Friday, December 4, 2026!
📻100万部突破記念📻
ヤンマガWebで1巻無料キャンペーン実施中！期間は10/19まで。
この機会にぜひご覧ください！https://t.co/bsHc2M90r6 pic.twitter.com/moqFQEkebx— 【公式】妹は知っている (@imoutoknows) October 13, 2026
Mari Kanki’s “My Little Sister Knows”: Synopsis (Recap) of the Previous Volume, Volume 9
Synopsis of the Previous Volume (Details on the Previous Volume, Vol. 9)
I want to know more about that person.
Department Head Yokoo and Momi Tiger have confessed their feelings to each other. Gin’hiko, a coworker, can’t stop thinking about Kiichiro.
All sorts of things happen again today around the brother and sister who live next door to each other—.
Volume 9 of the ever-entertaining sibling comedy.
© Mari Kanki/Kodansha
Introduction to Mari Kanki’s “My Little Sister Knows”
My older brother is Fruit Parfait, the legendary postcard artist.
At work, he’s seen as a boring, expressionless office worker—Kiichiro Miki.
He stands out even at drinking parties and never seems to be having any fun.
But I, his little sister, am the only one who knows the truth.
That he’s actually “the funniest and kindest person in the world”—.
A heartwarming sibling comedy that gently touches your heart!
© Mari Ganki/Kodansha
Mari Kanki’s “My Little Sister Knows” Latest Volume 10 on Sale Friday, December 4!
© Mari Kanki/Kodansha
| Buy the Complete Series | [Amazon]Kindle E-book Bundle |
|---|---|
| Release Date | December 4, 2026 |
| Author | Mari Kanki |
| Price | To be determined *As of October 15, 2026 |
| ISBN | To be determined *As of October 15, 2026 |
| Information on the Previous Volume | Detailed Information on Volume 9 of “My Little Sister Knows” |
| Related Links | “My Little Sister Knows” Young Magazine Web Official Site |
“My Little Sister Knows” Comic Product Information
人気作品のキャラクターグッズ Anime Store.JP (アニスト) にて取扱中！
／
㊗️「妹は知っている」公式アカウント開設🎊
＼100万部突破を記念して公式アカウントが出来ました！@imoutoknows
↑のアカウントをフォロー＆引用元のポストをリポストで50名様にオリジナルQUOカードが当たります🎯今後ヤンマガ本誌関連の情報はこちらで更新されていきます。… https://t.co/Dtv7KL1Doo pic.twitter.com/0az6b7568X
— 雁木万里 (@yanuimori) October 12, 2026
Please check the official website for details.
*Please note that the information in these articles may be out of date. We apologize for the inconvenience, but please check the official website for the latest information.
© Mari Kanki/Kodansha
