Nigotta Hitomi no Lilianne - Chapter 14 – Fairy and Study and

Luo Feng was reborn back in his high school years. From the start, he acquired the Return On Investment System.

[Invest in this coffee shop and you will be able to open many branches in the future. It has an ROI of 100%.]

[Invest in Bitcoins and the price will skyrocket in the future. It has an ROI of 10,000%.]

[Invest in the cute girl who is the deskmate in class and she will become your wife in the future. It has an ROI of infinity.]

Luo Feng decisively chose to invest in his future wife.

…

Many years later, during a press conference, a reporter asked, “Mr. Luo, your White River Investment Company has surpassed Morgan Stanley and Goldman Sachs, becoming the most famous investment management company. In your opinion, what is the most successful investment you have made in your life?”

Luo Feng looked at his wife fondly as he replied, “Don’t ask me. I just live off my wife.”

This novel is also known as Magic Industrial Empire

A prestigious senior mechanical engineer in the industry, Xu Yi was sent to a world dominated by magic.

In a world with an almost non-existent industrial system, how can Xu Yi display his value?

When magic collides with modern technology, when magic merges with machinery, that is the beginning of this story.

- Description from Novelupdates

In a galaxy far away, there is a kid without innate ability to practice internal techniques. So, in order to gain the respect of his father, he resolutely chooses to follow the more difficult and painful path of practicing external techniques. As the years go by, he grows up, but what really changes his life is a mysterious meteoric crystal stone – the Meteoric Tear. This stone fuses with the young man’s body unnoticed, and he seems to undergo drastic transformations as a result. After that, everything is changed. Eventually his father knows that the son for whom he hasn’t really shown a lot of consideration possesses astonishing abilities. And there’s a lot more to come.

An otaku with a hobby of masturbating was reincarnated as the son of a great mage.

As soon as he was born in this life, he vowed with a goal of embracing women till his death.

That said, when he became 20 years old, the Demon Lord which was sealed by his ancestors revived, and now it is his role to seal it once again.

And that demon lord is sealed in a tower dungeon that is rumored to be impossible to capture.

However, by an unexpected coincidence, he had found out that the Demon Lord is also one of him, a kindred spirit from within,

so he joined her instead and filled several traps in the tower dungeon, and thus they enjoyed a s*x spree with all the women coming over!