Eucliwood Hellscythe hails from the Underworld, though much of her past remains shrouded in mystery, including how long she resided there and the full extent of her activities. It is known, however, that she was a member of the Seventh Abyss, a powerful faction within the Underworld. During her time there, Eu formed a close friendship with Naegleria Nebiros, a skilled craftsman who designed Eu’s armor and gauntlets to help suppress her formidable powers.

Eu had actually been living in Tokyo long before she met Ayumu, although exactly how long is unclear. Their fateful encounter occurred outside a convenience store, where Ayumu approached her, attempting to initiate a friendship. Initially, she rejected his offer, but soon after, she saved him from an attack by a serial killer who had been terrorizing the area. Unfortunately, Ayumu’s injuries were fatal, prompting Eu to use her powers to resurrect him as a zombie, despite the physical pain it would cause her. This act of compassion marked the beginning of their connection, with Eu ultimately becoming Ayumu’s first housemate, setting the stage for their enduring bond and the events to come.

Eucliwood and Life at the Aikawa Residence

Approximately a month after the traumatic incident that claimed Ayumu’s life, Eucliwood continues to live quietly alongside him, their days marked by simple routines. Eu’s daily life consists of eating the meals Ayumu prepares, taking naps, and exchanging occasional written messages with him. This peaceful, if somewhat monotonous, lifestyle takes a dramatic turn with the arrival of Haruna, a spirited Masou-Shoujo who declares her “temporary” residence in Ayumu’s home.

Following Haruna’s arrival, Eu also invites another individual to join the household: Seraphim, a skilled vampire ninja. Although Eu declines Sera’s offer to serve as her devoted protector, Sera remains close, pledging to watch over Eu and the others. With Seraphim as the third housemate, the once quiet Aikawa residence transforms into a lively—and occasionally chaotic—hub of supernatural activity and unlikely friendships, redefining the lives of everyone involved.

By the end of the light novel series, Eucliwood has settled into a NEET lifestyle. While the series concludes on an open-ended note, there is speculation that Eu has become Ayumu’s wife, hinted at through rumors spread by his co-workers.

Ayumu Aikawa
Eucliwood and Ayumu share an exceptionally close bond, one that began under unusual circumstances but has since grown into a deep, mutual affection. Although they met only a month before current events, their connection is nearly unbreakable. Ayumu has been drawn to Eu since their first encounter, developing a strong crush on her. His fascination with her often borders on protective, with Ayumu fantasizing about her showing affection or speaking kindly to him, despite his humorous “little sister” complex.

Eu, who generally restrains her emotions to avoid causing harm, begins to open up gradually, especially after the encounter with the King of the Night. She even expresses her feelings aloud on rare occasions, such as during her battle against Ayumu’s inner demon of laziness. In this confrontation, she reveals her feelings, saying, “You are not the Ayumu that I love” (translated in English as, “You are not the Ayumu that I fell in love with”), a moment that hints at her deeper emotions for him. Despite her reserved demeanor, Eu values Ayumu as a trusted friend, a loyal companion, and even, in jest, a “friendly servant.” Her acceptance of his affectionate fantasies and willingness to stay by his side suggest she may share these repressed feelings.

At the close of Volume 19, it’s implied that Eu and Ayumu may have married, possibly living together with their other close friends.

Haruna and Eucliwood.

Haruna
Eu’s relationship with Haruna is quirky, with Haruna viewing Eu as a sort of “big sister,” although she frequently denies this, preferring to act as the elder sibling herself. Despite this playful rivalry, they genuinely care for one another. When Haruna told Ayumu to “drop dead” during a heated argument, Eu, who takes the concept of death seriously, uncharacteristically slapped Haruna, underscoring her deep respect for life. Despite these occasional clashes, their bond remains strong, each showing concern for the other’s well-being.

King of the Night
The King of the Night was once a young man whom Eucliwood resurrected as a zombie, much like Ayumu. Initially, they shared a profound connection, with the King rising to prominence in the Underworld. Over time, however, he succumbed to dark ambitions, accumulating power and ultimately killing a member of the Seventh Abyss, an elite rank within the Underworld. Horrified by his actions, Eu attempted to destroy him, heartbroken by the betrayal of someone she once considered close. This tragic relationship underscores Eucliwood’s compassionate nature and her commitment to protecting those she cares about—even if it means facing painful choices.