Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 1 - 1-2. Written Dream Read as Ephemeral

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

No family, no power, no inheritance — a thrice-lacking protagonist. Just how will the seed rise up from the mud?

- Description from Novelupdates

In the presence of strangers, Han Chen was always handsome and cold, making it difficult for others to get close to him. He was like the frosted snow – pure, and slightly chilly. Yet, he was also like the river flowing in the dark night – quiet and moving. To many, he was akin to an unparalleled and untouchable god.

Only in the presence of Bai Jin Xi would this famous top police superintendent expose his deeply hidden shameless nature.

“Come and sit nearer to me, I won’t eat you. At least, not now.”

“I have never touched other women before. Do you want to check my body?”

“Bai Jin Xi, never ever leave my side. Every year, every month, every moment, every minute, every second.”

In her heart, there exists an obstinate old man – one who has tirelessly loved her throughout all these years.