Life of Being a Crown Prince in France - Chapter 627 - 536: The Crown Prince’s "Mistresses

One day, Yoichi who grew up while not knowing his parents has received the news of his father’s death. His father left behind a testament——which said he is to pick only one out of five ‘little sister candidates’?!

Born as a hybrid, I was ab*sed by my maternal grandfather because I was a useless child who didn’t inherit any abilities from my dad’s family, and ended up dying.I returned to the past with my memories, but my options weren’t so different from the past.I’ll either live like this and be ab*sed to death just like in my previous life, or I’ll go to my dad who hates me.‘I don’t want to die again.’Eventually I went to my dad who hated me, with a locket in my hand that would prove me to be the daughter of the Black Leopard family.“Let me…let me stay here.”All I asked for is protection until I became an adult. Then, when I was old enough to live alone, I was going to go out and live without causing trouble. Because I was going to be a good kid this time.But, somehow…“My beloved daughter, if there is anyone who touches you, I will kill them immediately.”My father, who I thought hated me, was so sweet to me.“Hey, Perfi, don’t keep hugging Thiel. At this time of year, I heard that girls are very delicate.”“Where did you learn that s*upid theory? Thiel likes to hug.”The two brothers who I thought were scary like me so much.“Thiel, I’m going to hand you over the head position of this Black Leopard family.”My paternal grandfather suddenly tells me that he is handing over his position to me.Hey …didn’t everyone hate me?

When I became a rich young master, I had to enjoy it.
Training? No!
That is so boring.
I have a system, no need for training.

Are you hungry? Come, I will treat you with some food at a luxurious restaurant.
What a poor homeless. Come, I will give you a house.

I, Lin Fan is a good person.

- Description from Novelupdates

The second prince has come of age. To celebrate the advent of such an occasion, the search for a suitable bride began. My younger sister was expected to go to the Royal Palace as a candidate. However, despite this, she eloped the day before her departure. I, the older sister she left behind, looked almost exactly like her – so much that we were often mistaken for twins…

One month, right? For just one month, shall I substitute in for my sister?