Cathulhu Online, MUNYA! - Chapter 335 Cat Dad Travels To Mermaid Kingdom

Li Ke Lin (also Li Colin), a Chinese office worker, woke up to find himself suddenly no longer Li Ke Lin but instead Colin Lee, son of multi-billionaire in America. Having taken over the body of Colin Lee and carefully imitated his manners and bearings, his next goal is to inherit his father’s wealth. However, when his father lists the condition of marrying a woman who feels repulsed by Colin Lee’s (not Li Colin’s) dalliances, and whose very nature is the complete opposite of Colin Lee (not Li Colin), what must he do to gain her affection?!

Village doctor Zhang Xiaoshan attained a variety of Divine Skills.Mind-reading, treasure appraisal, and miraculous healing, he became capable of everything.

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

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.