Nine Moons in a River of Stars: Phase One by Xen.

And never came up again.

Welcome to a town where the rules of normal no longer apply. Where the sun will not rise, and the moon refuses to set. Where the people are beginning to change, beneath the haunted moonlight.
And where a boy whose heart does not beat begins to transform into something monstrous. Something terrifying. And only his love for his childhood best friend may keep his soul intact.
All Sho Asawa has ever wanted was to confess his love to Naoki Okubo, and run away from Marrow together. But as a strange barrier descends on the town, as creatures of myth and legend whisper in the dark…
…it may already be too late to escape.