Real name Onodera Shotaro. Was known as Ishimori Shotaro before 1986.

While he was in high school, made his debut with Nikyu Tenshi in Manga Shônen (1954). Like most of the Japanese artists, Ishimori was influenced by TEZUKA Osamu. In 1956, he formed a coterie group with AKATSUKA Fujio, NAGASHIMA Shinji and SUZUKI Mitsuaki. He moved to Tokyo after graduation, where he continued to work as a mangaka, starting with the war story Kaiketsu Harimao in 1959. Subsequently, he produced hit mangas such as the science fiction series Cyborg 009 (1964) and the historical series Sabu to Ichi Torimono Hikae (Big Comic, 1968-72). Other 1960s work by Ishimori are Yuureisen (1960), Mutant Sabu (1961), Shounen Doumei (1962) and Genma Taisen (1967),
as well as the humorous Bon Bon (1965).

In 1975, he began another historical series, Sandarabocchi, which ran until 1981. In the 1970s, Ishimori created metamorphosis manga such as Kamen Rider and in the 1980s, he became a pioneer of a new category of manga. He published Hotel in 1984, followed by the educational Manga Nihon Keizainyumon (1986) and the cynical look at society, Kuro Daikoku. In 1985, in order to celebrate his 30th anniversary as a manga artist, he changed his name to Ishinomori. In 1989, he commenced working on a large series about the history of Japan, Manga Nihon no Rekishi, which remained unfinished due to the artist's death on January 28th, 1998 at the age of 60. In 1995 an asteroid was named after 'Kamen Rider'.

Ishinomori was nicknamed the 'King of Manga' and is considered one of the pioneers of modern manga. He was also one of the most productive creators, producing over 120,000 pages of artwork in thirty years. It's rumored that he drew over 500 pages in one month!

His son ONODERA Joe, is a director and actor.

He was once an assistant of Tezuka when living at Tokiwa-so and roomates with AKATSUKA Fujio. They often fought over cleaning up ashtrays, both of them were heavy smokers.

NAGAI Go, OTA Gosaku and OZE Akira were once his assistants. YAMADA Goro, HOSOI Yuuji, SUGAR Satou, MIYAYA Kazuhiko and SUGAYA Mitsuru were his staff at ISHIMORI Pro.

TAKEMIYA Keiko is honorary disciple of his, growing up inspired by him.