Kaibutsu

A mysterious existence that suddenly appeared before Reishin. A beautiful girl dressed in a black sailor uniform.

An alien lifeform discovered by a scientist that copies the appearance of the victim it eats and makes the person the victim loves the most their mate. Driven by hunger, she eats Yuuko. Half of her obsession and love are caused by Yuuko, who resides in her mind and lies mostly dormant. Marries Reishin late in the novel and slowly learns to speak. Knows how to manipulate Reishin well.