Hello Mr. King - Chapter 43

Lin Tian, who had reincarnated into the world of One Piece ten years ago met Garp, who was on duty to eradicate pirates, and become his student.

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

This story is set during the end of the Sui Dynasty, a time where multiple powers struggled for supremacy and power.

Into the fray enters two orphans Kou Zhong and Xu Ziling; these two youths by many chances and luck obtain ‘The Secret to Long Life’ allowing the two to obtain profound martial abilities and a chance to rise to the top in this age of turmoil.

All I ever wanted was for famous detectives like Sherlock Holmes or Arsène Lupin to appear in my dreams and share their wisdom. But instead, why am I hearing the voices of notorious serial killers in my head, guiding me to solve a string of mysterious cases?