Haruaki Katoh is a Japanese manga artist and illustrator, born on December 19, 1981, in Aichi Prefecture, who later grew up in Oita Prefecture. He made his professional debut in 2006 with the online serialization of the manga Hyakko, which was published on the FlexComix Blood website. Hyakko is a slapstick school-life comedy that follows the daily hijinks of four high school girls, and Katoh served as both the story and art creator for the series.

The success of the original manga led to its adaptation into a thirteen-episode television anime series in 2008. Following the television series, an original animation video titled Hyakko Extra was produced and released on October 8, 2009, bundled with the fifth volume of the manga. For this OVA, Katoh is credited as the original creator and original plan author.

Beyond his own original work, Katoh has contributed illustrations to other projects under the alias Sanada Juuichi. He provided illustrations for the fifth episode of the D-Frag! television anime series in 2014 under this pseudonym. His published works also include a short manga titled Yuuhi Romance from 2007 and illustration work for a light novel in 2008.