The Summer Hikaru Died manga volume 5 features story and art by Mokumokuren.

Yoshiki has resolved to walk alongside the “something” that replaced his friend, Hikaru. But changes begin to appear, not just in the village, but also in the impostor himself! As they sense their current lives moments from crumbling down, the boys continue their investigation into “Hikaru's” identity. The history of Kubitachi, the truth of “Nounuki-sama,” and the “Indous' sin”… what will the answers to these mysteries mean for “Hikaru” and Yoshiki?!