Shin-Ei Animation
is a Japanese manga series written and illustrated by Marimo Ragawa. It has been serialized in Kodansha's "shōnen" manga magazine "Monthly Shōnen Magazine" since December 2009 and has been collected in twenty-seven "tankōbon" volumes. An anime television series adaptation by Shin-Ei Animation aired from April 3 to June 19, 2021 on the Animeism programming block.