Born on May 8, 1973, in Tokachi, Hokkaidō, Japan, Arakawa was born and raised on a dairy farm with three elder sisters and a younger brother. Arakawa thought about being a manga artist “since [she] was little” and during her school years, she would often draw on textbooks. After graduating high school, she took oil painting classes once a month for seven years while working on her family’s farm. During this time, she also created dōjinshi manga with her friends and drew yonkoma for a magazine.

Arakawa moved to Tokyo in the summer of 1999, and started her career in the manga industry as an assistant to Hiroyuki Etō, author of Mahōjin Guru Guru. Her own career began with the publication of Stray Dog in Square Enix’s Monthly Shōnen Gangan in 1999. Stray Dog won the ninth 21st Century “Shōnen Gangan” Award. She published one chapter of Shanghai Yōmakikai in Monthly Shōnen Gangan in 2000.

In July 2001, Arakawa published the first chapter of Fullmetal Alchemist in Monthly Shōnen Gangan. The series spanned 108 chapters, with the last one published in July 2010, and the series was collected in twenty-seven volumes. Some reviewers say that the combination of Arakawa’s art style and the writing in Fullmetal Alchemist contribute to its dark thematic elements. When the studio Bones adapted it into an anime series, Arakawa assisted them in its early development. However, she was not involved in the making of the script, so the anime had a different ending from the manga, which she developed further. The series won the 49th Shogakukan Manga Award in the shōnen category in 2004. When the second anime adaptation was reaching its ending, Arakawa showed director Yasuhiro Irie her plans for the manga’s ending, making both end in near dates. Most reviewers distinguish between the manga and anime, which they attribute to differences in style and subject matter. One review explains that the manga is more “emotional,” whereas anime is more whimsical. Arakawa’s simple, dark style and plot choices contrast with the anime’s “cartoony,” colorful rendering. Reviews in general tend to ascribe the anime to children and the manga to teens and adults.

Arakawa is married with three children. She gave birth to a son in 2007 and had her third child in January 2014.

In April 2011, Arakawa began a new series called Silver Spoon in Shogakukan’s Weekly Shōnen Sunday. Rather than writing another fantasy series like Fullmetal Alchemist, Arakawa wanted to challenge herself by trying a more realistic story with Silver Spoon. It quickly rose among Shogakukan’s best-selling titles and an anime series by A-1 Pictures began airing in July 2013. Also in July 2013 she began her manga adaptation of Yoshiki Tanaka’s The Heroic Legend of Arslan series of novels in Kodansha’s Bessatsu Shōnen Magazine.