Yūichi Kimura is a Japanese author, illustrator, and creator of picture books and childrens literature, born in Tokyo on April 14, 1948. He is a graduate of Tama Art University. Before becoming a full-time writer, Kimura worked in arts education and served as a creative director for childrens television programming. He also gained experience working at a mannequin company and a design office while pursuing freelance writing and design projects on weekends and holidays. Kimura has stated that his father passed away when he was ten years old, which instilled in him an early sense of responsibility and a desire to support his family through creative work he genuinely enjoyed.

Kimura is the author of the acclaimed picture book series Arashi no Yoru ni, also known as One Stormy Night. The first book was published by Kodansha in 1994 and was originally intended as a standalone story. The series eventually grew to seven volumes, concluding with Mangetsu no Yoru ni (One Full Moon Night) in 2005. The story follows an unlikely friendship between a goat named Mei and a wolf named Gabu who meet and bond in a dark shed during a storm. The series has sold over 1.3 million copies in Japan and has been incorporated into Japanese school textbooks. For the first book, Kimura received the Kodansha Literature Culture Award for Picture Books and the Sankei Childrens Literature Culture Award.

Beyond Arashi no Yoru ni, Kimura has authored an extensive body of work comprising up to 500 literary pieces. He has also written books such as Hot Hot Pancakes and On the Seesaw Bridge, along with a series of baby books. Early in his career, he created papercraft projects for magazines and a notebook based on the popular manga Great Mazinger.

The Arashi no Yoru ni series was adapted into an animated film released in 2005, directed by Gisaburō Sugii. The film won a Japan Academy Award in its category. Kimura personally contributed to the films screenplay. In 2012, a computer-animated television series adaptation titled Arashi no Yoru ni: Himitsu no Tomodachi (One Stormy Night: Secret Friends) aired on TV Tokyo for 26 episodes. Kimura is credited as the original creator for this series.

An interview with Kimura provides insight into his artistic identity. He deliberately left the goat character Mei without a specified gender to allow readers to interpret the story more broadly, and he has expressed interest in seeing how international audiences respond to the themes of friendship and difference. Kimura used distinct dialects for the wolf and goat to help readers easily distinguish between the two characters in dialogue-heavy text. He has cited illustrators such as Seizo Tajima, Makoto Wada, Shinta Cho, and Hiroshi Abe, who illustrated the Arashi no Yoru ni series, as significant influences and favorites.