Aihara grew up reading the works of Tezuka Osamu. 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, Koujien, 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 Super Nintendo RPG Maka Maka.
