Oninaki is an action RPG exploring themes of life, death, and reincarnation, following Kagachi, a Watcher who guides lost souls to the afterlife while battling monstrous beings known as the Fallen. Combat revolves around Daemons, lost souls bound to Kagachi who grant him different weapons and abilities.

Players switch between Daemons to adapt combat styles on the fly, moving between the world of the living and the Beyond as the story unfolds. It's built for fans of narrative-driven action RPGs willing to explore heavier themes.