Kaiju No. 8 , also known in English as Monster #8, is a Japanese web manga series written and illustrated by Naoya Matsumoto. It was serialized on Shueisha's Shōnen Jump+ app and website from July 2020 to July 2025, with its chapters collected in 16 tankōbon volumes. Shueisha has also published the series digitally on its Manga Plus platform in English and several other languages. Viz Media began publishing the series digitally in August 2020 and has published the series in print in North America since December 2021.