Elena Aoki is a fair-skinned young woman with short dark blue or black hair and striking red eyes. She has a slim and more modest physique compared to her younger sister, Clair. Elena’s demeanor is often calm and composed, in stark contrast to the chaos surrounding her transformation.

She is commonly seen wearing a brown hat, which adds a subtle touch to her overall appearance.

In her monster form, Elena transforms into a large, ghost-like creature with a gloomy, eerie presence. Her appearance becomes unsettling, with long, flowing hair that further emphasizes her otherworldly and haunting nature.

Elena Aoki is an emotionally unstable and dangerous character, embodying the traits of a yandere a person whose love is obsessive and violent. She harbors a deep, possessive crush on Shuichi Kagaya, which makes her shy and timid around him. However, this affection is tainted by a selfish, murderous attachment, and she becomes dangerously fixated on him.

Elena is responsible for transforming Shuichi into a monster, intending to “become one” with him by entering his body in a manner similar to Clair. Her mental state is volatile, shifting from psychotic outbursts to moments of unexpected calm. She is capable of switching from murderous rage to a more docile attitude in an instant. For example, after attacking Shuichi with the intent to kill, she immediately calms down and even apologizes when she realizes he is still alive although she later shifts back to violence upon discovering the presence of Clair inside him. Her obsession with Shuichi and her need to possess him take a dark turn when she decapitates him to determine who the girl inside him is, showing her complete disregard for any boundaries or lives, including Shuichi’s.

Manipulative and cunning, Elena prefers to use others as pawns rather than directly engaging in violence herself. She demonstrates a chilling lack of remorse for her actions, which highlights her cold, calculating nature. Elena’s capacity for murder is demonstrated by her indifference to killing her own parents, a deed she commits without hesitation. Both Shuichi and Clair are horrified upon realizing the extent of her murders, and they fear that she is a true monster one whose actions are driven by an unhinged desire for control.

Despite her emotional instability, Elena retains moments of lucidity, particularly when it comes to her younger sister. After killing their parents, she spares Clair, claiming she did it for her sake, and even gives her a coin she believes could be useful. Upon discovering Clair inside Shuichi’s monster form, Elena’s aggression momentarily subsides, and she gives Clair another coin before leaving, signaling a complex, albeit twisted, form of affection.

Elena Aoki, after finding a mysterious coin, uses it to have her wish granted, transforming Shuichi Kagaya into a monster. This act sets off a chain of events that drastically changes the lives of everyone involved.

When Shuichi and Clair Aoki finally track Elena down, Clair attempts to confront her, only to reveal that she is inside Shuichi’s monster form. As Clair tries to kill Elena, Shuichi intervenes, making her miss her shot. Elena, visibly shaken, transforms into her monstrous form, and the confrontation freezes both Shuichi and Clair in fear. However, Elena quickly begins apologizing to Shuichi, displaying an unexpected remorse for her actions.

The group retreats to a more private location, where Elena wonders if Shuichi has learned about her from the Alien. She begins to suspect that Shuichi knows she was the one responsible for turning him into a monster. Shuichi, who has no memory of the events, is confused and doesn’t fully understand her implications. But then, Clair’s voice emerges from inside Shuichi, and upon hearing her sister, Elena’s demeanor changes. In a fit of madness, Elena tears off Shuichi’s mascot head, desperate to see who is inside. The moment she sees Clair, she realizes what she’s done and begins apologizing profusely.

After the initial shock, Elena and Clair exchange words. Clair asks about their parents, and Elena reveals painful truths: their father was a corrupt politician, and their mother had a young lover. Elena explains that she killed them for Clair, as Clair had once expressed a desire to kill them herself. Elena no longer needed protection, and this act of violence was her way of showing strength.

Before leaving, Elena gives Clair another coin, telling her to use it wisely. She then receives a phone call and departs, leaving Clair with more questions about their past and the complex, twisted bond between them.

The name “Elena” is composed of the kanji 江 (e), meaning “bay” or “inlet,” 麗 (re), meaning “beautiful” or “lovely,” and 奈 (na), meaning “apple tree.” The combination of these kanji evokes a sense of natural beauty, with the imagery of a bay or inlet conveying tranquility and elegance, while the “apple tree” adds a touch of warmth and growth.

Elena’s surname, “Aoki,” is made up of the kanji 青 (ao), meaning “blue” or “green,” and 木 (ki), meaning “tree” or “wood.” This combination suggests a connection to nature, particularly the vitality of trees and the calming colors of blue and green, symbolizing life and growth.