The Case Study of Vanitas is a Japanese manga series written and illustrated by Jun Mochizuki. It has been serialized in Square Enix's shōnen manga magazine Monthly Gangan Joker since December 2015. In North America, the manga is published in English by Yen Press.

Gangan is a manga imprint owned by Square Enix Holdings. It originated as a manga imprint for Enix before the company re-branded as Square Enix. It publishes manga in several anthologies aimed at different reader demographic groups in the Japanese market. Its anthologies are home to some popular Square Enix manga series which were adapted into anime series, like Fullmetal Alchemist, Moribito: Guardian of the Spirit, Nabari no Ou, Inu x Boku SS, The Case Study of Vanitas and Soul Eater. The comics are later collected in paperback volumes under brand names such as Gangan Comics , Gangan Comics Joker and Young Gangan Comics , which identify the anthology of serialisation. These paperback brand names are formed by omitting any gekkan or shōnen in the magazine name and inserting Comics directly after the word Gangan.