The rumors circulating on social media were finally confirmed when mangaka Mokumokuren announced on his official X account on May 24, 2024, that The Summer Hikaru Died is getting an anime adaptation.

Mokumokuren revealed an illustration to celebrate the announcement.

As part of the adaptation, an official X account and website were also launched.

Further details about the anime adaptation, such as format, staff, cast, and release date, have not yet been revealed.

The Summer Hikaru Died began serialization on Kadokawa Shoten's Young Ace Up website in August 2021.

Mokumokuren first conceived of the series while studying for exams and later began posting drawings on Twitter, which led the editorial department of Young Ace Up to approach Mokumokuren to serialize the manga through the Young Ace Up website.

As of December 2023, the individual chapters of the series have been collected into four tankōbon volumes.

MAL describes the manga's plot as:

Best friends Yoshiki and Hikaru have been stuck together like glue for most of their lives. Living in a small village and being the only children their age, the two boys find comfort in each other's company. Their friendship seems quaint at first glance, but Yoshiki has noticed a change in Hikaru's behavior since one fateful summer.

The “Hikaru” who sits next to him now looks nothing like his friend. Despite his physical appearance and memories remaining exactly the same, Yoshiki knows something is wrong and that the Hikaru he once knew is gone. When he mentions this, Hikaru partially transforms into an otherworldly being, threatening to kill Yoshiki if he cannot accept this—all the while professing his love for him.

Wracked with grief and unable to let go of his best friend, Yoshiki struggles to move on with his life as he grows closer to the new Hikaru. At the same time, strange events begin to plague his village, bringing unsettling chaos..

Source: X (1, 2)