Tokyo Ghoul: [JACK] is a oVA anime that premiered in summer 2015, produced by Studio Pierrot.

About the production: the story comes from a manga, there is 1 episode of about 30 minutes and its current status is "finished".

Its main genres are drama, horror and supernatural, with themes such as School, Seinen, Delinquents and Gore.

On AniList, Tokyo Ghoul: [JACK] has an average score of 70%, a good score, and appears on 61,184 users' lists.

The franchise continues in or follows from: Tokyo Ghoul.

Former baseball player turned delinquent Taishi Fura accidentally witnesses the man-eating "ghoul" known as Lantern injuring his old friend and murdering another. Before the situation gets any worse, Fura's classmate Kishou Arima arrives―as he is actually an undercover investigator for the Commission of Counter Ghoul (CCG)―and forces the ghoul to flee. Seeking revenge for his friends, Fura joins forces with Arima to hunt down ghouls in the 13th Ward—ultimately aiming to bring down Lantern. Tokyo Ghoul: "Jack" unveils snippets of life in the past for the CCG's fearsome "Reaper," Arima, giving insight into how he spent his high school days. (Source: MAL Rewrite)

Official synopsis from AniList.