Roy is an orphan boy living in a city that thrives thanks to labyrinths. One day, he enters a stray labyrinth that is considered a "loser" and gets lost in a mysterious tower. There he finds a large amount of rare materials and slimes that eat them. Seeing this, Roy recalls his lost memories... he was a [pharmaceutical] slime in his previous life! With his awakened skills and the technology of ancient civilizations, Roy decides to live a free and easy pharmaceutical life. He is surrounded by a diverse group of friends, from his slime partner to a half-elf girl and a cat fairy who loves ancient documents! The curtains rise on a lively and happy life as a pharmacist...!
