Kaoru Nagase died unexpectedly while walking home from her office job one night, and she suddenly finds herself before a man dressed in white. The man introduces himself as God and apologizes for the mistake that caused her untimely death, promising to compensate Kaoru by reincarnating her into another world. Celestine, the goddess of the next world, reforms Kaoru's body and grants her all the concessions she requests: the body she had at age 15, the ability to create potions with effects of her choosing, and a box with infinite storage space, among others. However, Kaoru soon realizes that, contrary to what she was told, this new medieval world lacks significant magic, making her potions highly sought after by greedy nobles. Nevertheless, by applying knowledge from her previous life, she may find a way to survive in this world using her potions.