Azusa Aizawa is the main protagonist of her story, a former Japanese office worker who died from overwork at the age of twenty-seven. In her previous life, she was a black-haired woman who worked so relentlessly that she once logged fifty consecutive days without a break, a fact that directly led to her death. Taking pity on her, a goddess offered to reincarnate her into a new world where she could live a happy, relaxed life. Azusa’s one wish was to be granted eternal youth and immortality, ensuring she would never have to rush through her days again. She was reborn as a beautiful, ageless witch with the appearance of a seventeen-year-old, characterized by her long blonde hair, often braided, and blue eyes, typically dressed in a classic witch’s pointed hat and black coat.

Her primary motivation is the preservation of a quiet, slow-paced existence, a direct rebellion against the crushing workload of her past life. To this end, she settled in a small cottage on a highland near the village of Flatta, intending to live a simple life as a local herbalist. For three centuries, she sustained herself by hunting approximately twenty-five slimes each day, selling the magical crystals they dropped. Unbeknownst to her, an innate ability that doubled her experience points caused her level to climb steadily over the years. After 300 years of this unambitious routine, she discovered she had reached the maximum level of ninety-nine, making her one of the most powerful beings in the world. This revelation, however, brought the opposite of what she wanted. News of the "Highland Witch's" immense power spread, attracting challengers, adventurers, and legendary creatures to her doorstep, disrupting the very peace she had worked so hard to achieve.

Despite her deep-seated desire to avoid trouble and keep to herself, Azusa possesses a fundamentally kind and charitable nature that makes it impossible for her to ignore those in need. This contradiction is the driving force behind her role in the story. Rather than a grand hero seeking adventure, she is a reluctant matriarch whose good deeds inadvertently expand her family. She cannot turn away a dragon who challenges her and subsequently destroys her home, instead accepting Laika as a disciple to teach her the value of a relaxed life. When the lingering spirits of the slimes she killed for centuries coalesce into two young girls, she immediately takes on the role of their protective and doting mother, naming them Falfa and Shalsha. Similarly, she offers shelter to Halkara, a bumbling elf fleeing a misunderstanding with the demon Beelzebub, and later invites Rosalie, a lonely ghost, to live in her home. In this way, her quest for solitude continuously results in the growth of a lively, unconventional household, and she evolves from a solitary hermit into the caring, if occasionally exasperated, core of a diverse found family.

Her key relationships are all built on this maternal and mentoring foundation. She is deeply attached to her slime spirit daughters, Falfa and Shalsha, and is known to be especially indulgent with them while fiercely protective against any threat. Laika, the red dragon, becomes her first devoted disciple, while the elf Halkara becomes her second, often causing trouble with her inventions. Her friendship with the demon minister Beelzebub begins with a duel but quickly evolves into a close camaraderie, with Beelzebub frequently visiting and teaching Azusa demon-summoning magic. She also forms a unique bond with Pecora, the Demon King, who becomes infatuated with Azusa’s strength and insists on treating her like an older sister. Throughout these interactions, Azusa consistently acts as a grounding force, using her own trauma from overwork to remind her friends and family to rest and not push themselves too hard.

Throughout the narrative, Azusa experiences a notable development from a recluse who actively avoids deep connections to a woman who has fully embraced her role as a mother and mentor. She learns to accept the chaos that comes with her growing family and even uses her abilities to protect and nurture them. Her power also evolves. Initially stuck at the human limit of level ninety-nine, she later receives a blessing from the goddess for her courageous actions, breaking her limits and ascending to a "god-class" level, granting her even greater strength. This development, however, does not change her core personality; she remains someone who would rather use her phenomenal cosmic power to do laundry with a tornado or make sweets for a village festival than to conquer anything.

As for her notable abilities, Azusa’s primary strength lies in her maxed-out status, granting her immense physical and magical power, including superhuman strength, durability, and agility. While she can use a wide array of magic, from elemental attacks like fire and lightning to teleportation and magic reflection, she rarely does so. She is far more likely to rely on her overwhelming physical stats to simply overpower opponents with brute force, though she has no formal martial arts training and is often described as being full of openings. One of her unique powers is "Create Magic," the ability to invent entirely new spells. Despite her god-like power, she has several comedic weaknesses. She is terrified of ghosts and cannot see them unless they materialize, and she has no natural resistance to status ailments from things like poison mushrooms. She is also self-conscious about her modest chest size and has a notoriously poor sense for naming things and creating songs. Fundamentally, Azusa is an immensely powerful but perpetually relaxed individual whose greatest wish is not to use her power for glory, but to protect the peaceful, happy life she has built with her unconventional family.