Azusa Aizawa was a 27-year-old Japanese office worker whose life ended due to fatal overwork after 50 consecutive days without rest. A goddess reincarnated her into a fantasy world as an immortal witch, granting her requested eternal youth and agelessness. Her new form resembles a 17-year-old European-styled teenager with long blonde hair often braided around her head, blue eyes, and typical witch attire: a pointed hat, black coat, white blouse with a yellow cravat, and a dark blue skirt.

Seeking to escape her workaholic past, she settled near the rural town of Flatta, adopting an intentionally slow-paced life. For 300 years, she sustained herself by hunting roughly 25 slimes daily, selling the dropped magic crystals. Unbeknownst to her, an innate skill doubling her experience points maximized her level to 99. The discovery of this unprecedented power disrupted her desired isolation, attracting challengers and visitors seeking her strength or aid.

Her solitude shattered when the red dragon Laika arrived for a challenge. Azusa defeated Laika by inducing a brain freeze during combat and demanded repairs for her damaged house. Laika subsequently became her disciple and household helper. Later, the accumulated spirits of slain slimes coalesced into two sentient daughters: the affectionate Falfa and the initially vengeful Shalsha. Though Shalsha attacked with specialized anti-witch magic, Azusa pacified her. Both daughters joined the household, with Azusa embracing a deeply protective and nurturing maternal role.

Further disruptions followed. Halkara, an elf fleeing the demon Beelzebub over an energy drink misunderstanding, joined after Azusa resolved the conflict. Azusa also aided Rosalie, a ghost haunting Halkara's prospective factory, inviting her to reside with them. Attendance at Laika's sister's wedding led to conflict with blue dragons led by Flatorte; Azusa intervened using gravity magic, forcing a peace pact. This act earned her the Demonic Medal of Honor from Demon King Pecora, further elevating her reputation.

Azusa possesses maxed stats—Magical Power, Agility, and Intelligence at "999+"—enabling diverse magic: elemental manipulation, teleportation, barrier creation, and magical reflection. A unique "Create Magic" ability allows her to invent spells. Her immortality grants superhuman strength, durability, and reflexes. Despite these capabilities, she avoids combat unless necessary to protect her family or preserve her peaceful life, her core ideal.

Personality-wise, she prioritizes harmony and resists overwork, often enforcing breaks on others like Laika. She exhibits hospitality, forgiving former adversaries and forming bonds across species. While she avoids romance to prevent the pain of outliving partners, she cultivates strong familial closeness with her household, referring to them as chosen family. Minor insecurities include dissatisfaction with her breast size compared to her previous life.