is a Japanese manga series written and illustrated by Hideki. It began serialization in Ichijinsha's "Monthly Comic Rex" magazine in January 2018.






Media.
Manga.
Written and illustrated by Hideki, "1-nen A-gumi no Monster" began serialization in Ichijinsha's "Monthly Comic Rex" magazine on January 27, 2018. Its chapters have been collected into fourteen "tankōbon" volumes as of February 2025.
Other.
In commemoration of the release of the series' third volume on July 27, 2019, a promotional video was released on Ichijinsha's YouTube channel that same day.