Zero no Tsukaima - Volume 2 Chapter 5

On the day of her escape from prison, she had died unexpectedly and was reborn into the body of Madam Huo.
He was the heir to the number one financial magnate. She had charged out of nowhere and from then on, the obedient and weak Madam Huo had started to awaken. She had been trampled under her feet.
Huo Shao had expressed that since she had already been conquered, wouldn’t it be too unfair for her if she did not give her body to him?
The muzzle of the gun was aimed at her head, “I only lost my wife and did not divorce. Choose between loving me or dying for love. ”
Gu Ruochu,”…”
Do I still have a choice?

- Description from webnovel

Growing up with eccentric materialist parents who left him in the care of his grandfather for a job overseas, Zhang Heng had learned to adapt and be unfettered by the oddities and challenges in life. But he would soon learn the baffling truth about the world he thought he knew when one day at midnight time froze and he found himself in a world so quiet and still it was deafening. That night, he discovered that he had 24 hours more than everybody else and thus, marked the beginning of his adventures. The mysteries surrounding his newfound ability only deepened when a strange old man claimed to have given Zhang Heng that ‘gift of time’ and recruited the young man to participate in a cryptic ‘life-changing’ game on his behalf. Little did Zhang Heng know that accepting those terms meant embroiling himself in many versions of reality and exposing himself to the hidden secrets of the world—a decision he could never undo.

During the summer vacation, sixteen nieces came to Luo Feng’s house to play together, but they couldn’t go back when the city was closed.

He silently calculated that the 16 nieces had to eat 16 catties of rice, 8 catties of meat and 20 eggs a day.

Total other consumption, need 3000 yuan per day.

Just when he was trembling, Uncle Shenhao’s system descended!

Just pet your niece to get rewards!

Explode the street with my niece, reward: an extended version of Rolls Royce.

Take your niece to the supermarket, reward: 30 million supermarket coupons.

Take your niece to eat out, reward: 100% shares in Dihao Hotel.

Teach my niece to write, reward: a house in the school district.

Book a movie theater for my niece, reward: shares in Yida Company!

Hold a luxurious birthday party for your niece, reward: the design drawing of the world’s strongest aircraft carrier!

With this system, I take my 16 nieces everywhere to eat, drink and have fun every day.

Accidentally, he became the richest man in the world…

- Description from novelbuddy

There’s a legendary Bishoujo Game that has become popular among Japanese gentlemen.