I Don’t Want This Reincarnation - Chapter 7

A 30-year-old NEET is reincarnated into the body of an otaku that choked to death on instant noodles. As he comes to grips with his new life, he realizes that this world is subtly different from Earth. The denizens of this world are far better looking, and this new world also possesses futuristic technology as well as mysterious Yin Yang masters!

After reincarnating, he realized that he was endowed with a miraculous game-like system, which enables him to increase his own stats and transcend the limits of the human body. This system even has a game-breaking ability to save and load in real life!

In this new world that’s akin to a 2-D game, he just wants to enjoy life and head for a glorious future… However, he is quickly embroiled in a complex plot. Can he unlock his true potential and utilize his system to break the shackles that confine him and discover the truth about his previous body’s circumstances?

- Description from novelupdates

A teen is summoned to another world as the Hero. It turns out the Hero can power up women with his cum.

The dark underground dungeon was filled with countless ancient relics and treasures. Eerie, deformed, cursed objects... The abyss, catacombs, Ancient Gods, mythical races... Mechanics, cursed seal implants, and the gargantuan black towers... A peculiar mix of Alchemy, a drop of steampunk, two spoons of supernatural mystery, blending into a vibrant and colorful fantasy world. I am a puppeteer Alchemist. All that my eyes behold, becomes my puppet. Alone, I am an army!

After Reincarnating into Naruto World at the Warring State Era as an Uzumaki, Masahiko thought that he got a useless System. He lived for 48 years as a normal, below average Uzumaki Shinobi.

That changed when he finally knew how the system works the day of his 49th Birthday!

- Description from Novelupdates