Mikio Igarashi is a Japanese manga artist and original creator, born on January 13, 1955 in Miyagi Prefecture, Japan. He is best known as the creator of two long-running and award-winning manga series, Bonobono and Ninpen Manmaru, also known internationally as Manmaru the Ninja Penguin. He made his professional debut as a manga artist in 1979 with the works '80, Those Days and Nekuratopia. Before his debut, he left technical high school before graduating and worked at an advertising agency and a printing company.

Igarashi is the writer and illustrator of the manga Ninpen Manmaru, which was serialized in Enix's Monthly Shōnen Gangan magazine from April 1995 to April 1999 and compiled into eleven volumes. The story follows Manmaru, a young penguin who attends the Nenga Ninja School and becomes involved in conflicts with rival ninja schools. The manga was adapted into a forty-eight episode anime television series produced by Shin-Ei Animation, which aired on TV Asahi from July 5, 1997 to March 28, 1998. A 3D platform video game based on the series was also released in 1997 for the Sega Saturn, published by Enix.

His most famous creation is the manga Bonobono, which began serialization in 1986 and has continued for over three decades. The series centers on a young sea otter and his animal friends in a forest. Bonobono has been adapted into multiple animated works. Igarashi personally directed and wrote the 1993 Bonobono movie and the 2002 film Bonobono: Kumomo no Ki no Koto. He also provided voice work for these films. A television anime series aired from 1995 to 1996, and a second series began broadcasting in 2016.

Igarashi is primarily known for his work in the four-panel comic strip format. While his early career focused on gag comedy, his later works, beginning with Bonobono, have moved towards a more philosophical and gentle style. He has also created works with heavier themes, such as the horror manga Sink and I, a series about the nature of God. His other notable manga include Kamurobamura-e, Kyou wo Aruku, and Hitsuji no Ki, the latter of which is an adaptation of a story by Tatsuhiko Yamagami.

Throughout his career, Igarashi has received significant industry recognition. He won the Excellence Award at the 12th Japan Cartoonist Association Awards in 1983 for Anta ga Warui. He received the Kodansha Manga Award for general manga for Bonobono in 1988. In 1998, he won the Shogakukan Manga Award for children's manga for Ninpen Manmaru. He also received an Excellence Award at the 18th Japan Media Arts Festival in 2014 for Hitsuji no Ki and the Excellence Award at the 46th Japan Cartoonist Association Awards in 2016 for Dare mo Inai Tokoro no Keshiki.