After a lifetime of mundane routine and corporate drudgery, Azusa Aizawa meets an unexpected demise due to overwork. Rather than venturing into the afterlife, she encounters a goddess who grants her eternal life in a tranquil parallel world. Azusa spends centuries peacefully farming, safeguarding her village, and dispatching a modest 25 slimes daily. However, her uneventful existence takes a turn when she realizes she has attained the remarkable level of 99 solely by battling slimes. Fearing unwanted attention, Azusa strives to conceal her immense power, but rumors of her legendary status spread like wildfire. Soon, a diverse array of beings, including the dragon Laika and elf Halkara, seek her out for duels or aid. As Azusa forms deep bonds with these newfound companions, she discovers that life is infinitely richer when shared with others, transforming her solitary existence into a vibrant tapestry of friendship and camaraderie.