Ena is a male Shikabane and a member of the Shichisei, the group of rogue undead that the series' protagonist pursues. He is known for his androgynous appearance, characterized by dark green hair and olive eyes. His undead nature grants him a unique curse: the ability to transfer his consciousness from one corpse to another, provided a suitable body is nearby. This makes him exceptionally difficult to destroy, as he can simply abandon a damaged vessel for a fresh one. His primary weapon is a large, spinning metal ball that has the power to grind nearly anything it touches into dust.

Before becoming a Shikabane, Ena was a sculptor who harbored an all-consuming obsession with capturing true beauty in his art. He used a young boy as his model, seeking inspiration from the child's form. When the boy accidentally injured himself, spoiling his physical perfection, Ena flew into a rage. It was in that moment, as the boy resisted and struggled against his anger, that Ena had a twisted revelation. He believed he found true beauty in the precise instant when life, fighting against death, finally succumbs to its inevitability. After strangling the boy to death to capture this moment, Ena used the corpse to create a macabre display. He worked obsessively on this project until he died from exhaustion, but his obsession was so powerful that his spirit possessed the boy's corpse, allowing him to continue his work as a Shikabane. He would go on to kidnap and murder other young people in an attempt to replicate his initial artistic epiphany.

Ena's personality is defined by his manic devotion to his aesthetic ideals. He is theatrical and flamboyant in his actions, with other members of the Shichisei noting his performative nature. His obsession with beauty has completely superseded all other instincts, including his own self-preservation. He is driven not by a desire for power or revenge, but by the singular need to witness and recreate the fleeting moment when life gives way to death. This unwavering dedication made him a valuable asset to the Shichisei, and he was recruited by their leader, Hazama, who recognized the purity of his violent art. In the service of this group, Ena directly participated in the massacre of the Hoshimura clan, delivering the mortal wounds that led to the protagonist Makina Hoshimura becoming a Shikabane Hime.

In the second season, known as Corpse Princess: Kuro, Ena plays a pivotal and devastating role. He is responsible for the death of Keisei Tagami, a central character and the original Contracted Priest of Makina. Ena accomplished this by using his body-hopping curse to possess the body of Ouri Kagami, Keisei's younger brother, forcing him to stab the priest. This act has profound consequences for the story. Ena's end comes in a confrontation with Makina, who has gained a new level of power through her contract with Ouri. Makina is able to shatter Ena's spinning metal ball, which serves as the anchor for his curse. With its destruction, Ena is rendered vulnerable. Before his final moments, the nature of his obsession is fully revealed: having never possessed true beauty himself, he had long ago committed suicide and spent his existence as a Shikabane constantly transplanting different corpse parts onto his own body, desperately trying to construct an ideal form. After this revelation, Makina destroys him, ending his long, obsessive quest for beauty in death.