Bailonz Street 13 - Chapter 141:

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’?!

He used to think Death was the end.He was wrong.Death was but another beginning, a new adventure.Reborn into this strange and familiar world, he should have been dead, his soul fading into nothingness, but he found himself in a completely new existence. Now, as a Primordial instead of a human, he must find his place in this wondrous world.

“You’re not taking me to bed. Ever.”

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?