The Boundless Abyss

Hikaru Kageyama lived as a typical shrine apprentice, following customs and obligations—until he broke the seal of an old relic one night. In a flash, flames and disorder took over his life waking up Kagutsuchi, an evil fire god locked away for hundreds of years. Now, a cursed mark ties him to Kagutsuchi's unstable might pushing Hikaru into a secret realm where creatures born from people's fears—Manifestations—threaten to destroy everything.

The mysterious Boundary Keepers bring Hikaru into their fold where he must figure out how to use his curse as both an attack and a defense. But as he goes deeper into this risky world, he starts to see that Kagutsuchi isn't just along for the ride in his body—the deity has its own agenda.
As old feuds come back to life and Manifestations gain strength, Hikaru finds himself walking a tightrope between humanity and destruction. His fiery teacher, Takumi Arata, and his best friend, Kaito Sakamoto, stand by his side as Hikaru faces unrelenting foes tough decisions, and the constant murmur of Kagutsuchi's voice in his mind.

As the boundary between hero and monster starts to fade, Hikaru must choose: will he harness Kagutsuchi's power to rescue the world—or will he be the one to set it aflame.