Yen Press publishes the manga in English and describes the story:
“You are not a true comrade.” After finding himself unable to keep up with the hellish fighting on the front lines of the war against the demon lord's army, Red is finally kicked out of the Hero's party. Ashamed of his inadequacy, he moves to a distant frontier region where nobody would know his face or past. However, once he gets over the funk of having to leave his adventuring days behind, he's actually excited to begin a quiet life as an apothecary…which becomes a whole lot more lively when a former party member and actual princess, Rit, pays him an unexpected visit!
Ikeno launched the manga adaptation in Monthly Shōnen Ace in May 2018. Kadokawa published the manga's first compiled book volume in December 2018, and will publish the 14th and final volume on August 26.
Mutsuki Higashiōji launched a spinoff manga titled Rejected by the Hero's Party, a Princess Decided to Live a Quiet Life in the Countryside (Shin no Nakama ni Narenakatta Ohime-sama, Henkyō de Slow Life Suru Koto ni Shimashita) in Kadokawa's Shōnen Ace Plus magazine in October 2021. The series ended on January 24, and Kadokawa published the third and final compiled book volume on February 26. Yen Press will release the first volume of Higashiōji's spinoff manga on August 20.
Zappon began serializing the story on the "Shōsetsuka ni Nārō" website in October 2017. Kadokawa began publishing the story in print with illustrations by Yasumo in June 2018. Kadokawa published the novels' 14th volume on May 1, and it revealed that the series will end in its 15th volume.
The novels' anime adaptation's first season premiered in fall 2021. (The show's staff had delayed the anime from July to October of that year due to "various circumstances.") Funimation streamed the season as it aired in Japan. Crunchyroll is streaming the first season.
The anime's second season premiered on January 7. Crunchyroll streamed the series as it aired.
Source: Monthly Shōnen Ace September issue