It's Not Easy to Be a Man After Travelling to the Future (WN) - Chapter 6: A Shameless Person

Yo, Hi! I’m Frank, I made a deal with a demon to pay me some money for receiving a guest for a few days every week.
I had no idea about what I have done.
On May 1st, Conan ‘the God of Death’ came to my house. I was forced to let him in and we get involved in a criminal case.
On May 8th, Bruce Wayne ‘Batman’ came to me. I was forced to follow him to fight crime.
On May 16th, Hannibal Lecter, The Silence of the Lambs, came to my home. I can only say that I really can’t stand my guests.

- Description from Novelupdates

10 years ago, after “the Gate” that connected the real world with the monster world opened, some of the ordinary, everyday people received the power to hunt monsters within the Gate. They are known as “Hunters”. However, not all Hunters are powerful. My name is Sung Jin-Woo, an E-rank Hunter. I’m someone who has to risk his life in the lowliest of dungeons, the “World’s Weakest”. Having no skills whatsoever to display, I barely earned the required money by fighting in low-leveled dungeons… at least until I found a hidden dungeon with the hardest difficulty within the D-rank dungeons! In the end, as I was accepting death, I suddenly received a strange power, a quest log that only I could see, a secret to leveling up that only I know about! If I trained in accordance with my quests and hunted monsters, my level would rise. Changing from the weakest Hunter to the strongest S-rank Hunter!

A decision can destroy the sun, moon and stars. A finger can kill the Heavenly Overlord. While chatting, the Heaven and ten worlds can be annihilated.

#Expect a big Harem but MC won't mindless collect women on a whim. There's deep mature content. Beware!After getting rejected and humiliated by the very woman he's ever loved—and publicly dumped during lunch break in front of half the school while holding a giant teddy bear, blue roses, and a handwritten love letter titled “My Heart in .mp3”—Jayden Cross thought life couldn't get worse.Then he wakes up with a system talking in his ear.[Ding! Welcome to the Ultimate Copy and Paste System!][Function Unlocked: 10x Copy and Paste!]Now armed with a divine-level Ultimate System Jayden begins rebuilding his life with just copying and pasting everything and gets 10X more!What the world, the system, and the universe had shattered without remorse, only the Ultimate Copy and Paste System could restore. But it did not simply mend—it reimagined. It rewrote his broken existence into a force no storm could contain, only follow.