The first episode of Isekai Yakkyoku (Parallel World Pharmacy), titled establishes a grounded take on the isekai genre by blending modern medical science with a medieval fantasy setting. Plot Summary

The story begins with Kanji Yakutani, a world-class Japanese pharmacologist obsessed with his work. His relentless drive stems from a childhood tragedy: the death of his younger sister from an incurable brain tumor. This obsession eventually leads to his death from (overwork) at the age of 31.

He awakens in the body of , a 10-year-old boy in a medieval-esque world who was recently struck by lightning. Kanji soon realizes he is now part of a prestigious family of royal pharmacists. However, he is dismayed to find that local "medicine" relies heavily on superstition, quackery, and expensive, ineffective treatments reserved only for the nobility.