Adachi Mitsuru (born February 9, 1951 in Isesaki, Gunma Prefecture, Japan) is a Japanese manga artist. After graduating from Gunma Prefectural Maebashi Commercial High School in 1969, Adachi worked as an assistant for Ishii Isami. He made his manga debut in 1970 with Kieta Bakuon, based on a manga originally created by Ozawa Satoru. Kieta was published in Deluxe Shonen Sunday (a manga magazine published by Shogakukan).
Adachi is well known for romantic comedy and sports manga (especially baseball) such as Touch, H2, Slow Step, Miyuki and Cross Game. He has been described as a writer of "delightful dialogue", a genius at portraying everyday life, "the greatest pure storyteller", and "a master manga artist". He is one of the few manga artists to write for shonen, shojo, and seijin manga magazines, and be popular in all three.
His works have been carried in manga magazines such as Weekly Shonen Sunday, Ciao, Shojo Comic, Big Comic, and Petit Comic, and most of his works are published through Shogakukan and Gakken. He was one of the flagship authors in the new Monthly Shonen Sunday magazine which began publication in June 2009. Two short story collections, Short Program and Short Program 2 (both through Viz Media), have been released in North America, and Viz Media scheduled to begin publishing Cross Game in October 2010. The first volume was released on October 12.
He modeled the spelling of あだち (rather than 安達) for his family name after the example of his older brother, manga artist Adachi Tsutomu. In addition, it has been suggested that the accurate portrayal of sibling rivalry in Touch may come from Adachi's experiences while growing up with his older brother. Adachi did the character designs for the OVA anime series Nozomi Witches, so he is sometimes incorrectly given credit for creating the original series.