Tanky Mage System - Chapter 440

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.

Haruma Kazuki is a cursed (or maybe just deeply unfortunate) high school student whose lewd, panicked, or absurd thoughts literally manifest in reality — especially when he tries not to think about them. The more he denies or avoids feelings, the more chaotic and trope-heavy the consequences.

Wang Yi gets a key, opening a door in 2022 will lead to 1982, and opening a door in 1982 will return to 2022.

Two very different great eras appeared before him:

Abundant dietary protection, developed industrial products, miraculous medicines, and explosive information, this is 2022.

Simple folk customs, rich wild resources, scattered antiques, and treasures of the age, this is 1982.

Traveling between these two eras, Wang Yi didn’t think much of it, he just wanted to live a good life.

- Description from novelbuddy

[You have become the master of the Warden Mansion.][Your first quest is to refine mana from one of your maids by having intercourse with her.]When nineteen-year-old Jett Talon suddenly wakes on an emperor-sized bed, he finds himself lord of a mysterious mansion where countless gorgeous maids stand ready to serve. His first companion is Mia, a blonde elven maid who checks his every box. After making love to her, Jett gains mana, unlocks legendary powers, learns his duties as Master of the Warden Mansion, and uncovers its hidden secrets.