The Summer Hikaru Died manga volume 1 features story and art by Mokumokuren.

Two boys lived in a village: Yoshiki and Hikaru. The two did everything together...until the day Hikaru was encompassed by a mysterious light. That was when everything changed—Hikaru most of all. Yoshiki still wishes from the bottom of his heart to always stay by his side...but is there even a Hikaru left to be with?