Hisaichi Ishii, born September 2, 1951 in Tamano, Okayama Prefecture, is a Japanese manga artist known for his prolific work in the yonkoma, or four-panel comic strip format. He graduated with a degree in sociology from Kansai University, where he was a member of the manga research club. His professional debut came in 1972 with the series Oh! Baito-kun, published in the job information newspaper Nikkan Arubaito Jōhō, which followed the struggles of students looking for part-time work. This work helped establish his style of social satire and observational humor.

Ishii first gained widespread recognition with Ganbare!! Tabuchi-kun!!, a baseball gag manga that ran in Weekly Manga Action from 1978 to 1979. The series was a satire of the world of professional sports and its media coverage, featuring a lazy, grumpy, and reluctant hero based on real-life baseball player Kōichi Tabuchi. The character’s fame surpassed that of his real-life counterpart, and the manga was adapted into three anime films released by Tokyo Movie Shinsha between 1979 and 1980: Ganbare!! Tabuchi-kun!!, Ganbare!! Tabuchi-kun!! Gekitō Pennant Race, and Ganbare!! Tabuchi-kun!! Ā Tsuppari Jinsei.

His most internationally recognized work began as Ojamanga Yamada-kun in 1980, a series that dissected the quirks, vanities, and daily struggles of a typical Japanese family. The strip evolved significantly when it began running in the serious morning edition of the Asahi Shimbun newspaper in 1991 under the title Tonari no Yamada-kun. The tone shifted from pure slapstick to a more nostalgic and melancholic reflection on family life, generational conflict, and the passage of time. In 1997, as the youngest daughter Nonoko, known as Nono-chan, became the most popular character, the series was retitled Nono-chan to reflect her central perspective. This iteration of the series received the Tezuka Prize for best compiled work in 2003.

The worldwide recognition for Ishii came in 1999 when Studio Ghibli director Isao Takahata adapted the Yamada family stories into the acclaimed animated film My Neighbors the Yamadas. A 61-episode anime television series based on Nono-chan was also produced by Toei Animation and broadcast on TV Asahi from 2001 to 2002. In 2010, his hometown of Tamano appointed Nono-chan as its official mascot character. Beyond these major hits, Ishii has created numerous other series covering a vast range of subjects including sumo wrestling, Edo-era ninjas and warriors (Ninja Mugeichō), politics (Ishii Hisaichi no Daiseikai), economics, and even a work about Hillary Clinton. He also worked as a character designer for the 1994 SEGA CD game Ishii Hisaichi no Daiseikai.

His artistic identity is defined by his sharp, satirical eye and his mastery of the yonkoma format. Rather than heroic tales, his work focuses on the failures, absurdities, and small indignities of everyday life, whether in the context of a professional baseball player, a salaryman father, or a bickering family. He is known for his extreme caricatures of public figures and a willingness to tackle serious political and economic issues through comedy. Despite his significant influence and popularity, Ishii is known for being a private individual who grants few interviews. In late 2009, he placed the daily Nono-chan strip on hiatus to receive medical treatment for an unspecified, non-life-threatening illness, marking a brief pause in a career of daily, consistent publication.