Natsuko Heiuchi is a Japanese manga artist born on June 30, 1960, in Kawasaki, Kanagawa Prefecture. She began her professional career in 1979 and won the Shonen Magazine Newcomer Award in 1982. Before creating her own series, she worked as a background artist on several anime productions in the early 1980s, including Tetsujin 28-gou, Ohayou! Spank, and Rokushin Gattai GodMars.

Heiuchi is best known as the original creator of the soccer manga Offside. The series was serialized in Kodansha's Weekly Shonen Magazine from January 1987 to April 1992, with its chapters collected into 29 tankobon volumes. The story follows Goro Kumagaya, a young goalkeeper who dreams of becoming a top soccer player. The manga was later adapted into a 50-minute original video animation released on January 22, 1993. A 39-episode anime television series adaptation, produced by Ashi Productions, aired on Animax from May 2001 to January 2002. The anime was directed by Seiji Okuda, with scripts by Takao Koyama.

Beyond Offside, Heiuchi has created numerous other manga series, many of which focus on sports and competition. Her body of work includes the J-Dream series about soccer, Road about running, Tennis Ace, and The Lowest Regatta in History about rowing. She also wrote Sky Without Tomorrow and Ikarosu No Yama. Her works are primarily published by Kodansha and fall within the shonen demographic, targeting young male readers. Her artistic identity is strongly tied to sports narratives, often emphasizing themes of perseverance, teamwork, and personal growth through athletic competition.