The story begins in a desolate future where civilization has crumbled. An ancient elf named Alfred, who once achieved great renown as a sage after defeating the Overlord Zilweith 400 years prior, now lives in solitude. He reflects on humanity's extinction 50 years ago and the world's impending collapse, marked by falling meteors. He visits the World Tree, Yggdrasil, a sentient being who has supported the world for 3000 years. Yggdrasil reveals her regret at becoming the World Tree, a sacrifice made when she was human. Alfred, moved by her plight and his own loss of emotion, makes a desperate wish: to be sent back 3000 years to save her. Yggdrasil grants this wish, and Alfred is sent back in time, reborn as a human baby.
Alfred awakens in the past, in the year 3016 before the current era, as a baby girl named Tearina, the daughter of Count Alaude Franks, a commander in the Imperial Knights. He is shocked to discover he has been reborn as a female but quickly accepts this new reality, driven by his mission to save Yggdrasil. Tearina possesses an immense spiritual power, far exceeding that of the future Overlord Zilweith, which allows her to manipulate mana and aura. However, she discovers that mana is scarce in this era, limiting her magical abilities. She focuses on aura manipulation, enhancing her physical strength.
Eight years later, Tearina, now a skilled swordswoman known as the "Prodigy of the Sword," trains rigorously with her father. She has embraced her new life, finding joy in her family and her burgeoning abilities. She forms a rivalry and friendship with Prince Jikuroyd, the third prince of the empire, who is also a talented swordsman. Their intense duels showcase Tearina's exceptional speed and power, surpassing even her father's abilities. During one such duel, Tearina's extraordinary power causes significant damage, impressing Jikuroyd and earning her widespread recognition.
Tearina's peaceful life is disrupted when she hears a slave girl named Miu crying for help. Tearina intervenes, saving Miu from an abusive slave trader. She uses her abilities to heal Miu's wounds and buys her freedom with a precious earring gifted by Jikuroyd. Miu, a member of the "Tra tribe" (cat-like beastfolk), becomes Tearina's loyal attendant.
Later, while playing in the garden, Tearina is abducted by the same slave trader, who orchestrated the incident to extort a ransom from her father. Tearina awakens in a dark underground prison with two other captives, Louise and Shia. She learns they were captured by bandits. A mysterious voice calls out to Tearina, offering her a powerful sword, Gram, a cursed demonic sword. Louise warns Tearina against it, but Tearina, remembering a past tragedy involving Gram, decides to wield it to save herself and her companions.
Tearina uses Gram's power, amplified by her own aura, to defeat the bandits. However, her immense power and bloodlust, amplified by Gram, terrify Louise and Shia. Tearina realizes she is losing control and urges them to escape. Meanwhile, Jikuroyd, alerted to Tearina's abduction, mobilizes the knights to find her. A ransom note arrives, demanding a large sum of money.
Tearina, consumed by bloodlust, slaughters the bandits, her actions becoming increasingly demonic. She is horrified by her own transformation and the realization that she is a danger to those she cares about. She manages to regain some control and escape the prison with Louise and Shia, but not before the slave trader escapes with the ransom money and Tearina's precious earring. Tearina pursues him, driven by the desire to retrieve her earring, and in the ensuing chaos, she falls into a lake. Jikuroyd finds her and pulls her to safety. Tearina, realizing her feelings for Jikuroyd and the danger she poses, resolves to protect him by first fulfilling her mission to save Yggdrasil.
