The manga debuted in Japanese on Shonen Jump+ on January 5. Viz Media and Shueisha's MANGA Plus debuted the manga in English on January 4. The manga's first volume released in Japan on April 4.
MANGA Plus describes the story as: "Front-line stories of the Defense Force not covered in the main series!"
Matsumoto launched the ongoing Kaiju No. 8 manga in July 2020 on Shueisha's Shonen Jump+ website. Viz Media is releasing the manga in English digitally and physically. Shueisha also publishes the manga digitally on its MANGA Plus service under the title Monster #8.
The manga inspired a television anime that premiered on TV Tokyo on April 13. Crunchyroll is streaming the anime with English subtitles, and it is also streaming an English dub. The anime streamed on X (formerly Twitter) as well worldwide in real time as it aired on TV in Japan, at the exact time the anime aired. The anime will have a sequel.
The franchise also has an upcoming game for smartphones and PC.
Source: Kaiju No. 8: B-Side chapter 11