Pest ga Aketara Asobimashou!- Chuusei Europa Sekai to Gendai Bunmei Slow Life

In 14th Century Middle Age Europe, the spread of the Black Plague has led baker Rachel Becker to move from the city to a village. There, she meets Ema Muller, a "witch" who claims to come from "another world" 700 years into the future, bringing with her modern technology that feels like "magic" to the people of the middle ages...
(Source: Kadokawa, translated)