Twenty-five-year-old Higashiyama Tori dies after pushing a child out of the path of a truck. In the afterlife, a god rewards him for his unintended sacrifice by granting him reincarnation into a fantasy world. As a parting gift, Tori receives several magical abilities drawn by lottery, including medium-level swordsmanship, low-grade four-attribute magic, and one extraordinary skill: the highest-tier spatial magic.

Upon arriving in his new body, which retains his original adult appearance, Tori pursues a long-held dream. He aspires to become a mysterious, powerful figure who operates in secret, allowing his heroic exploits to become the subject of tavern rumors that he can overhear while enjoying a good drink. To achieve this dual life, he registers as a low-ranked one-star adventurer under his real name while planning to use his space magic anonymously.

Almost immediately after reincarnating, Tori encounters a party of knights and mages being overwhelmed by a colossal earth dragon. Seeing a perfect opportunity to generate those first crucial rumors, he intervenes, using his spatial magic to effortlessly defeat the monster and vanish. However, he soon discovers the scale of his actions far exceeds his expectations. The party he rescued is the White Sword, a nationally celebrated group of elite adventurers. The creature he killed was a legendary-class monster that even their top-ranked team could not defeat. Rather than becoming a minor local legend, Tori finds himself the subject of intense, kingdom-wide interest, and the beautiful members of the White Sword become determined to uncover the identity of their mysterious savior.

The story follows Tori’s struggle to maintain his secret. As the swordsman Tori, he is often scorned by other adventurers as an old rookie for starting his career at twenty-five, which ironically helps him avoid unwanted attention for his secret persona. As the unknown spatial mage, he attracts the relentless curiosity of the White Sword, particularly Marine, a powerful mage who feels a strange sense of nostalgia towards Tori’s mana. This leads her to frequently seek out and befriend his adventurer identity, drawing him closer to the very people he is trying to evade.

Key narrative arcs include the initial encounter with the earth dragon and its aftermath, where Tori deals with the guild's confusion and the White Sword's investigation. Another major arc, introduced in the second manga volume, involves a crisis of identity. When rumors spread of a mysterious magician operating in the royal capital, Tori realizes an impostor is using his alias. Forced to investigate, he travels to the capital while being followed by a persistent rival, the lightning mage Vivreweisen, leading to a confrontation with the fake and a deeper entanglement with the kingdom's politics. The story continues to explore Tori’s double life as he takes on more dangerous quests, forms uneasy alliances, and inches closer to the secret of why Marine finds his magical signature so familiar.