MTL - Deep Sea Survival: Start a Submarine (Deep Ocean Survival: A Submarine From The Start) - Chapter 1 Dive into the abyss

A mecha otaku is reincarnated into another world as Ernesti Echevalier (Eru). In this world there exist huge humanoid weapons known as Silhouette Knight. Dreaming of piloting those robots, Eru, with childhood friends, Archid Walter and Adeltrud Walter: together they will aim to become a Knight Runner, pilot of Silhoutte Knight.

What the heck? She, a famous doctor from the 23rd century, turned into a village peasant girl of a different world!

Her grandmother was cruel and vicious. Her aunt was very mean. So, to have a meal and clothing every day, she, a famous doctor had to pull up her sleeves to do farm work, treat patients, and abuse the bullies!

What? Grandmother need money for her illness? Cousin has no money to get a wife? Cousin needs to borrow money for his studies?

Roll! Roll as far as the history can go!

- Description from Novelupdates

The old man pointed to the flower-like woman and said, “Call her mother from now on.” He then pointed to a flower-bud-like girl and said, “This is your sister.”

My younger sister was not cute.

She was arrogant, taciturn and weird, but she knew how to please our parents.

She was two-faced and deceitful, but it seemed like she only treated me that way.

I cared for her, tried to please her as much as I can, but she still disliked me.

Until one day, I found out her secret, our relationship began to get a little bit weird…

What if your own father and his mistress were behind your mother’s death? What if you were about to be sold if to a scumbag?