Getting a Technology System in Modern Day - Chapter 4: First step

Being given a chance and reincarnated is nice and all, yet why do I have to become that male friend who just watches the protagonist flirting with his harem?---World: Kaguya-sama: Love Is War - Hyouka ----

When Zhou Shu woke up, he learned that he had become a Forging Apprentice at a workshop in the Forging Division of the Great Xia empire.

This is the story of a modern sailor who was accidentally reborn as a soldier of the Brazilian Expeditionary Force, and finally became the largest plutocratic family in Brazil by virtue of his foresight.

- Description from novelbuddy

Gu Qingli, a modern-day doctor and poisoner, was killed by her best friend. She was reborn as a weak peasant girl who could easily be bullied. Not long after she returned home, her wedding was called off. Everyone in the village started speaking poorly about her. A greedy matchmaker showed up and tried to convince Qingli to marry an older man! The matchmaker had barely been gone for a few seconds before returning once again. It seemed that Xiao Laosan, a man from the same village who was famous for bringing bad luck to his partner, wanted Qingli as his wife. The matchmaker wondered why a wretched woman like her was so popular. Gu Qingli did not mind. She thought that she, a wretched woman, was a perfect match for this man. For the days to come, she'd take her younger brother with her to forage for herbs, and they'd stir up trouble when they got bored. Wretched woman? A failed investment? Those things had nothing to do with her!