It was serialized in Shogakukan's seinen manga magazine Monthly Ikki from June 2003 to September 2014, with its chapters collected in five wideban volumes.

Period is Yoshino's last manga series, who died in April 2016.

Written and illustrated by Sakumi Yoshino, Period debuted in Shogakukan's seinen manga magazine Monthly Ikki on June 25, 2003.

[6] Shogakukan collected its chapters in five wideban volumes, released from May 28, 2004,[7] to November 28, 2014.

[8] Period is Yoshino's last manga series, who died on April 20, 2016, at 57.