Kaoru Nagase's life took an unexpected turn when she tragically passed away during her evening commute, only to find herself standing before a man clad in white. This enigmatic figure reveals himself as God and expresses remorse for the mistake that led to her untimely demise. In an effort to make amends, God pledges to grant Kaoru a fresh start by reincarnating her in another world.
In this new realm, the goddess Celestine assumes the task of reshaping Kaoru's physical form, granting her every request along the way: she regains the youthful body she possessed at 15, acquires the ability to craft potions with customized effects, and receives a bottomless storage container, among other boons.
However, Kaoru quickly realizes that, contrary to her initial expectations, this medieval world lacks the abundance of magic she had anticipated. As a result, her potion-making skills become highly coveted by avaricious nobles. Nevertheless, with her knowledge from her previous life as a guide, Kaoru may yet uncover a means to thrive in this unfamiliar world through the power of her potions.