Koji Aihara

 is a Japanese manga artist from Hokkaido.
Aihara grew up reading the works of Osamu Tezuka. He made his debut with "Hachigatsu no Nureta Pantsu" in 1983, which ran in "Weekly Manga Action Magazine". He is one of the authors of "Even a Monkey Can Draw Manga", a satiric look at the manga industry. Aihara's other best-known works include "Bunka Jinrui Gag", "Koojien", "Mujina" and "Manka". "Manka" has been described as being similar to tanka in that it shows the breadth of human emotion within the short space of a yonkoma. He has also drawn a yonkoma parody of a Japanese dictionary. His work has been described as breaking new ground for themes in comedic manga, and as showing "meticulous detail". He also designed the characters for the RPG video games "Maka Maka" and "Idea no Hi" (scenario and character design draft).