It was serialized in Shogakukan's seinen manga magazine Weekly Big Comic Spirits from May 2019 to August 2023.

In the small city of Nanao, insomniac Ganta Nakami tries to catch a nap in his school's abandoned astronomical observatory.

Written and illustrated by Makoto Ojiro, Insomniacs After School was serialized in Shogakukan's seinen manga magazine Weekly Big Comic Spirits from May 20, 2019,[11] to August 21, 2023.

[53] The Japanese band Macaroni Enpitsu [ja] released a music video for their single "Enshin" (遠心, "Centrifuge"), which featured art from the manga, on November 21, 2019.

[57] The series was also listed in the top 10 in the 2024 edition of the Young Adult Library Services Association's Great Graphic Novels for Teens.