Rosalie

Rosalie is one of the main characters in Slime Taoshite 300 nen. She is the ghost of a girl who died 140 years ago on the site of Halkara's Nutri-Spirit factory and haunted location until Azusa, Halkara, and Beelzebub helped to free her from her resting place.

Background

Rosalie, once known as a graceful and well-mannered young woman in the city of Nascúte, was the daughter of a wealthy merchant. During her lifetime, she lived in relative comfort and carried the poise expected of someone from a privileged background. However, her life took a tragic turn when her father's business collapsed, leaving the family in debt. In a desperate and unforgivable act, her father attempted to sell Rosalie to the Red-Light District, deceiving her by claiming she was to be married to a nobleman. Upon discovering the truth, Rosalie took her own life by hanging.

Her death was not the end. Because of the intense betrayal and pain she experienced, Rosalie's spirit became anchored to the site of her demise. Over time, the once-graceful girl was transformed into a foul-mouthed, short-tempered ghost, fiercely territorial and bitter. Her attachment to the land and the unresolved trauma from her life caused her to haunt the area, frightening the townspeople and making the land unusable.

Years later, the cheerful and clumsy elf Halkara unknowingly built her Nutri-Spirit Factory on the haunted land. The factory failed to attract workers due to the ghost's terrifying presence, prompting Halkara to seek the help of Azusa and Beelzebub. Through their efforts, Rosalie was exorcised—not in the traditional sense of being banished, but freed from the trauma that chained her to that place. She was welcomed into the House of the Highlands, where she found a new family and a second chance at life (or rather, unlife).

Now living among Azusa’s unconventional and loving household, Rosalie remains sarcastic and rough around the edges, but her true kindness and loyalty shine through as she grows closer to the others and begins to heal from the wounds of her past.

Appearance

Rosalie appears as a youthful teenage girl with medium-length strawberry blonde hair cut into a soft bob that frames her face, giving her a delicate appearance that contrasts her often sharp-tongued personality. Her light green eyes retain a glimmer of both melancholy and mischief, hinting at her tragic past and ghostly nature.

Her signature attire reflects both her lingering attachment to the human world and the era she died in. She wears a flowing purple dress adorned with twin rose-colored stripes, styled to resemble a sailor uniform (sera-fuku)—a nostalgic and haunting echo of her youth. The dress includes a white sailor-style collar lined with twin black stripes and a black neckerchief, further enhancing the schoolgirl motif. Topping off her outfit is a matching purple beret accented with a bright fuchsia bow, giving her a sense of old-fashioned charm despite her ghostly status.

However, Rosalie isn’t bound to this single look. Thanks to a transmutation spell crafted by Azusa, she can change her outfit freely—often donning different clothes to fit the occasion. One notable example was during Azusa’s commendation ceremony in the Demon Kingdom, where Rosalie appeared in an elegant formal dress, demonstrating that even in unlife, she takes pride in appearance and respects social occasions.

Personality

Despite being the daughter of a wealthy merchant and once known throughout Nascúte for her poise and grace, Rosalie’s personality now stands in sharp contrast to her noble upbringing. The betrayal by her father—who attempted to sell her to the Red-Light District under false pretenses—and her subsequent suicide by hanging scarred her deeply. The trauma of her death, coupled with years of isolation as a ghost, twisted her once-gentle nature into something far more abrasive and unrefined.

Rosalie became a foul-mouthed, brash spirit, fiercely territorial and unwelcoming to anyone who entered the place where she died. Her speech is laced with coarse language, and she often communicates in a corrupted form of the local dialect, as if her mannerisms decayed alongside her spirit. She openly admits, "Years of being dead have made me a bit… cheeky," which is something of an understatement given her confrontational behavior and colorful vocabulary. Her interactions with others are often punctuated by sarcasm, playful threats, and blunt honesty—even when it's far from socially appropriate.

However, Rosalie's personality is not without nuance. After being freed from the site of her death by Azusa—the Witch of the Highlands—Rosalie's demeanor began to change. Although still rough around the edges, she started to open up emotionally and even showed genuine affection and gratitude toward Azusa and the others. Her defensive personality gradually gave way to warmth, humor, and even protectiveness toward her newfound family.

This softening of her character didn’t erase her rough side—Rosalie remains proudly snarky and often clashes with others in humorous or exaggerated ways, particularly when possessing Halkara or making snide comments. Yet these traits now come from a place of belonging and love rather than bitterness and isolation.

In a way, Rosalie embodies the bittersweet duality of death and rebirth—a soul bruised by pain but given a second chance to live, laugh, and love, even if she does so with a ghostly growl and a sarcastic grin.

Powers and abilities

As a ghost, Rosalie wields a range of supernatural abilities that are typical of spirits, but with a flair that reflects her strong-willed and often mischievous personality. Her ghostly powers not only grant her an ethereal presence but also serve as both a comedic and practical tool within the household.

Core Abilities:

• Levitation and Flight: Rosalie can float effortlessly and zip through the air, which she often uses for dramatic entrances, sudden appearances, or just to loom overhead when making a sarcastic remark.
• Invisibility and Intangibility: She can vanish at will and pass through solid objects, which allows her to sneak around undetected or startle unsuspecting individuals—especially useful when haunting or teasing her housemates. This also makes her immune to most forms of physical harm.
• Poltergeist-like Manipulation: She can affect the physical world to some extent—moving or hurling objects, slamming doors, or generating unsettling noises. These abilities were once used to terrify the citizens of Nascúte, but in the Highlands, they’re mostly used for harmless mischief or minor home tasks (when she’s in the mood).
• Possession: Perhaps her most unique and troublesome ability is the power to possess others, particularly weak-willed or low-level individuals. Her most frequent victim is Halkara, whose panicky nature and lack of magical resistance make her an easy target. While possessed, Rosalie can fully control Halkara's body—often to comedic or chaotic results—but the experience is unpleasant for Halkara, to say the least.

Ghost Physiology:

• No Biological Needs: As a spirit, Rosalie is immune to hunger, thirst, fatigue, and aging, allowing her to function continuously without pause. Despite this, she often chooses to engage in eating or relaxing with the family, more out of social enjoyment than necessity.
• Magical Nature: Being a ghost, she is composed of spiritual energy and not bound to a physical body, which makes her invisible to normal detection unless one has spiritual or magical awareness. However, thanks to Azusa’s magic, she’s able to maintain a tangible presence within the home and even change clothes or appear in different outfits depending on the situation.

Rosalie’s ghostly condition comes with its ups and downs—while she’s liberated from the needs and limitations of the living, her emotions and personality remain very much alive. Her powers give her a unique edge in the group dynamic, often balancing comic relief with moments of unexpected depth and insight.