Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 3 - 3-5. The Japanese in Different World

The Return of the Heavenly Demon!I promised myself to live ordinarily for the rest of my life…….“Please be my father until I graduate.”He suddenly gained a daughter out of nowhere.

Cayena, the Imperial Princess, was known as the most beautiful woman in the Empire. She was a woman who knew nothing but evil and luxury.

However, she was destined for ruin: she would be used as a chess piece by her younger brother to secure his throne and killed by her crazy husband.

“I’ll make you the Emperor.”

“… Sister, are you referring to me?”

“In exchange, give me freedom.”

She had to change things before she became that Cayena.

[Have you become more learned today?][Accounting for the capacity of your brain, your study efficiency has been increased to 28 times that of normal.][The remaining amount of energy you have for studying today, 26 hours.][You will enter an exhausted state when your energy is depleted and be unable to obtain new information.][Please relax by using the functions within the system and restore your energy as soon as possible.]With limited energy and the onset of fatigue, the Study Monster had no time to think too much--papers to come!Had the heavens not grant me this system, the unending sea of knowledge would seem like a long night.

What the hell is this? What the hell happened here?