Isekai Yakkyoku, also known as Parallel World Pharmacy, is an ongoing, fantasy, Japanese manga series. After his sister dies from having an incurable brain tumor, Isekai Yakkyoku, a young Japanese pharmacologist, dedicates his life to study and research medicine and discover new treatments and medication so that no one else has to lose a loved one like he did.
He forgets the distinction between day and night and spends every minute researching only to die from overworking. He’s reincarnated in a parallel universe that seems to be a fantasy medieval europe. Reborn as a 10 year old apprentice to a famous Royal Court pharmacist, he figures out the people are extremely misguided and don’t have proper understanding of medicine.
He sets out to provide the people with effective and innovative medication that he had researched and developed in his previous life, wiping out the business of fraud pharmacists who were merely ripping people off. His reincarnation gave him magical abilities like seeing through a disease, material construction and deconstruction, etc.
However, these abilities came at a cost; after his reincarnation, Isekai Yakkyoku Manga has massive blessing marks on his arms that are believed to be from the medicine God and he doesn’t have a shadow anymore which is said to be a sign of the demon.
With his new abilities and knowledge, Isekai Yakkyoku overthrows the monopoly of the existing pharmacist guild and solves extremely complex cases that are too advanced for the medieval setting of the plot.
He eventually gets noticed by the Empress due to a complex case of tuberculosis and ends up opening his own pharmacy. This new life in the parallel world allows him to live the life he always wanted to, to the fullest.
