Azusa Aizawa is the main protagonist of her story, a witch whose quest for a quiet, leisurely existence inadvertently makes her the most powerful being in her world. Her journey begins with her previous life as a twenty-seven-year-old office worker in Japan, a period defined by an exhausting work culture that left her with no time for friends or personal joy. This life came to an abrupt end when she died from overwork, a fate that, while tragic, sets the stage for her second chance.

Upon her death, a goddess took pity on her and offered her reincarnation into a new world, with the promise of a life of happiness. Given the opportunity to make a single request, Azusa, who values rest and peace above all else, asked for eternal youth and immortality. Her wish was granted, and she was reborn as a seventeen-year-old witch, settling into a small home on a high plateau near the rural town of Flatta. For the next three centuries, she lived a life that was, by her standards, ideally simple and low-key. To support herself, she took up the modest task of hunting slimes, the weakest monsters in the world, and selling the magical crystals they dropped.

Azusa’s personality is the direct opposite of her former workaholic self. She is defined by her deep-seated desire to never be stressed or overworked again, leading her to adopt a relaxed, laid-back, and easygoing demeanor. She takes things at her own pace and encourages those around her to do the same. Despite her wish for a solitary and quiet life, she possesses a fundamentally kind and charitable nature. She finds herself unable to ignore the problems and troubles of others, which repeatedly pulls her away from her desired solitude. This contradiction is a core part of her character; she grumbles about the commotion but invariably steps in to help, welcoming a diverse group of individuals into her home as a result. Her past also makes her particularly sensitive to anyone who recklessly endangers their own life, as she values the second chance she was given.

Physically, Azusa has the appearance of a young European girl, with long blonde hair often tied up with a braid, and large, bright blue eyes. Her iconic outfit is that of a classic witch, consisting of a large pointed hat, a dark coat over a white blouse with a yellow tie, and a dark blue skirt. While she is considered beautiful, she does harbor a minor insecurity about her physical development, specifically the size of her chest.

Her three hundred years of daily slime hunting had an unforeseen consequence: she had unknowingly leveled up to the maximum of level 99, making her the most powerful individual in the world. Once this fact became public knowledge, her peaceful life was shattered as people seeking to test her strength or seeking her help began to appear. This event marks the true beginning of her role in the story, as she transitions from a solitary hermit to the heart of an ever-growing, unconventional family. Her role becomes that of a reluctant guardian and mentor, using her immense power to protect her loved ones and solve their problems, all while trying to maintain the facade of a normal, leisurely life.

The most significant aspect of Azusa's story is the family she builds. Her first new companion is Laika, a dragon girl who came to challenge her but ended up becoming her disciple after accidentally damaging her house. Azusa teaches her the value of a slow life. Soon after, she is discovered to be the unwitting mother of two slime spirits, Falfa and Shalsha, who were born from the slimes she killed over the centuries. While Falfa adores her, Shalsha initially harbors resentment, though she is quickly won over, and both come to call Azusa "mother". Her family continues to grow with the additions of Halkara, a well-meaning but clumsy elf; Beelzebub, a demon who becomes a close friend and fellow lover of sweets; and Rosalie, a ghost girl she helps free from a haunted building. Through each relationship, Azusa’s development is subtle but clear: she moves from a person who actively avoided deep connections to one who, despite her protests, fiercely cherishes and protects the chaotic family she has acquired. Even the goddess who reincarnated her remains a presence in her life.

As the most powerful being in the world, Azusa’s abilities are vast, though she rarely uses them to their full extent. Her primary, passive ability is immortality and eternal youth, the gift she requested from the goddess. Her stats are god-tier, with her magical power, defense, and agility all considered maximum or beyond measure. While her status lists a vast array of spells, including powerful elemental magic like tornados and blazing flames, she prefers to use her magic for practical, everyday purposes. She commonly uses magic for flying, cleaning the house with a tornado spell, teleportation, creating barriers, and crafting special clothes for her ghost friend. She is also a skilled herbalist, known as the "herb witch," and a surprisingly talented cook, having invented a sweet bean paste bun called "Edible Slime," which brings her unwanted fame as the "sweets-making witch".

Despite her power, Azusa has notable limitations. She rarely uses powerful offensive magic because she has so little practice with it that she cannot control the force, and she often prefers to rely on her immense physical strength in a pinch. She also has a strong, almost comical fear of ghosts and cannot see them unless they manifest physically. Furthermore, while her defense is high, she has no special resistance to status ailments caused by poison mushrooms or magic. Her journey is one of a former office worker who, after earning a peaceful retirement she never had, finds that true peace might just mean having a lively, loving, and slightly troublesome family to come home to.