In 1999, Joutarou Kuujou arrives at the Japanese town of Morioh for two reasons: to meet his illegitimate uncle Jousuke Higashikata and investigate a potentially dangerous Stand user. Only minutes after he arrives does he accomplish his first goal; however, Joutarou finds that Jousuke is not only a much younger high school student, but he possesses a Stand of his own called Crazy Diamond. Not long after their meeting, the two make a startling discovery: someone is using a supernatural bow and arrow to create Stand users around Morioh.

When Jousuke witnesses the threat that this poses, he resolves to protect his town and stop the spread of lethal Stand users. Finding both allies and enemies among these users, Jousuke learns just how much one's personal interests and ambitions can be reflected in their Stands, and the resulting harm or virtue it brings. As they continue to investigate, they begin to unearth the shocking history of Morioh, bringing forth hidden dangers and a mystery from years past.

JoJo no Kimyou na Bouken Part 4: Diamond wa Kudakenai was published in English as JoJo's Bizarre Adventure Part 4: Diamond Is Unbreakable by VIZ Media under the Shonen Jump imprint as 2-in-1 omnibus volumes from May 7, 2019, to May 4, 2021. The series was published in Italian by Star Comics from March 1997 to July 1999.

A live-action film adaptation of the series premiered in Japan on August 4, 2017.