月刊アフタヌーン
"Parasyte" was originally serialized in Kodansha's "Morning Open Zōkan" from 1988 and switched to "Monthly Afternoon" after a few issues, were it ran from 1990 to 1995. Kodansha collected its chapters in ten "tankōbon" volumes, released from July 20, 1990 to March 15, 1995. It was later republished in eight "kanzenban" volumes from January 21 to June 21, 2003.