Ren's childhood in the slums taught him that survival demands isolation and cunning. Kindness has no place in the streets that forge his existence. His reality shatters when a hidden tunnel reveals an ancient shrine sealed away from time itself. Within its walls stands a black cat with golden eyes—and a voice that speaks directly into his mind. This shrine holds secrets beyond mortal understanding. The cat exists as something far more dangerous. Drawn into an unfolding mystery that challenges him at every turn, Ren must choose between two impossible paths: embrace the ancient power calling to him through trials that demand everything, or fade back into the indifferent streets that never protected him. The city offers no salvation. But something lurks in the darkness—something that might. Experience a gripping tale of mystery and transformation, where each trial reveals the depths of Ren's true power. (No system, no isekai, no reincarnation, no regression, no harem. The story focuses on mystery and character development.)