Written and illustrated by Tsuyoshi Yasuda, Days was serialized in Kodansha's Weekly Shōnen Magazine from April 24, 2013, to January 20, 2021. Kodansha collected its chapters in forty-two volumes, released from July 17, 2013, to March 17, 2021.
Kodansha USA publishes the manga in a digital-only format since April 25, 2017.
Days volume list
DAYS～fragment～ volume list
References