Created by illustrator and cat lover Sayo Koizumi, this diary is a must-have for cat lovers, based on the concept of "becoming closer to cats."

The theme of the 2026 edition is "The Cats of the Koizumi Family." Illustrator Sayo Koizumi's diary features soft, gentle cat illustrations and columns. It's packed with the daily lives of the four unique felines of the Koizumi family.

In addition, this edition also sees the monthly schedule start in January and end in March of the following year, allowing you to manage your schedule right up to the end of the fiscal year.