Keigo Shinzo is a Japanese manga artist who made his professional debut in 2008. He was born on January 23, 1987, in Ishikawa Prefecture and is a graduate of the fine arts program at Tokyo Zokei University.

Shinzo's career began with the work "Nankin" in 2008. His early body of work includes several notable series and short story collections. He is the author of "Bokura no Funkasai" (Our Eruption Festival), which won a New Face Award at the 16th Japan Media Arts Festival. Other significant works include "Midori no Hoshi," serialized from 2013 to 2014, "Tokyo Alien Bros.," which ran from 2015 to 2017, and "Nora to Zassou," published between 2018 and 2020. He also released a short story collection titled "Sentimental Muhannou: Shinzou Keigo Tanpenshuu" in 2017.

Several of Shinzo's manga have been adapted for other media. "Moriyamachuu Kyoushuujo" (Moriyamachu Driving School) was made into a live-action film in 2016. "Tokyo Alien Bros." was adapted into a live-action television drama in 2018. His most acclaimed work to date is "Hirayasumi" (ひらやすみ), which has been serialized in Shogakukan's seinen manga magazine Weekly Big Comic Spirits since April 2021. "Hirayasumi" has been licensed for English release in North America by Viz Media. A live-action television drama adaptation aired on NHK General TV from November to December 2025, and an anime television series adaptation produced by Production +h. is scheduled to premiere on the same network in January 2027.

In 2020, during the COVID-19 pandemic, Shinzo was diagnosed with lymphoma. His experience with the illness inspired the one-shot "Akusei Rinpashu de Nyuuin shita Toki no Koto" (About the Time I Was Hospitalized for Malignant Lymphoma), in which he chronicles his recovery and the origin of the ideas for "Hirayasumi". He has stated that the concept for the series solidified while he was undergoing chemotherapy, and the story's focus on rest and a slower pace of life emerged directly from this period when he had no choice but to do the same. He took a hiatus from drawing "Hirayasumi" from October to December 2023, explaining that he needed more time to depict a summer vacation arc in a way that would leave him with no regrets.

The central themes of Shinzo's work, particularly in "Hirayasumi," revolve around rest, contentment, and the choice to step away from the pressures of career-building and societal expectations. The story follows 29-year-old Hiroto Ikuta, a carefree freelance worker who inherits a house from an elderly friend and becomes the guardian of his teenage cousin, contrasting his slow, unambitious life with those who are more driven. The work explores the idea that happiness can be found in peaceful daily life and human bonds rather than through major achievements. Critics have noted his compassionate approach to his characters, portraying their struggles with insecurity and comparison in a gentle, non-judgmental manner. The series is also noted for its detailed and expressive artwork, which effectively uses backgrounds and character body language to convey personality and emotion.

"Hirayasumi" has received significant recognition within the manga industry and beyond. It won the Bros. Comic Award from TV Bros magazine in 2021 and the 71st Shogakukan Manga Award in 2026. It has been nominated for the Manga Taishō awards, the Tezuka Osamu Cultural Prize, and has appeared on "Kono Manga ga Sugoi!" ranking list of best manga for male readers. Internationally, it was awarded the Gran Guinigi for Best Comic Serial at the 2024 Lucca Comics Awards in Italy. Established manga artists such as Inio Asano, Masakazu Ishiguro, and Taiyo Matsumoto have also offered positive commentary on the series. In a 2014 conversation with Matsumoto and Asano, Shinzo discussed his creative process, citing Tsuchika Nishimura as a peer and noting that his generation of artists was sometimes seen as a throwback to an older style of manga.