Photo/Illutration Rieko Nakagawa in an interview in April 2015 (Asahi Shimbun file photo)

Children’s author Rieko Nakagawa, known for her beloved “Guri and Gura” picture book series about twin field mice, died of old age at a hospital in Tokyo on Oct 14. She was 89.

Her family will hold a private funeral service and the chief mourner will be her eldest son, Kakuta.

It has not yet been decided whether a public gathering will be held to commemorate her life.

Nakagawa was born in Sapporo, Hokkaido, in 1935.

After graduating from Tokyo Metropolitan school where she studied to become a nursery school teacher, she taught at a children’s day care center in Tokyo.

While working there, she began writing her first book, “Iya Iya En,” which featured a preschool age boy who hated many things, and was published in 1962.

The following year, she published the first of the “Guri and Gura” picture books, in which the field mice twins find an egg in the forest, bake castella and share it with the other animals.

She was inspired to write it by the children at her day care center who loved a book called “Little Black Sambo,” which featured pancakes.

She said she wanted to “give the children an even better treat.”

Nakagawa’s books were illustrated by her younger sister, Yuriko Yamawaki (maiden name Omura). Yamawaki died in 2022.

The first book in the “Guri and Gura” series sold a total 5.71 million copies, making it a long-selling classic.

It has been translated into English, Chinese, Korean and other languages, and is loved by children all over the world.

The 22-book series has sold more than 22 million copies.

Among her many other children’s books are “Momo Iro No Kirin” (a pink giraffe) and “The Sky Blue Seed.”

She also wrote the lyrics of “Stroll,” the theme song for the animated film “My Neighbor Totoro.”

She and Yamawaki won the Kikuchi Kan Prize in 2013.