Chiteki de Cool na Kouhai Bijo, Ore no Kaineko ni Naru

I was in bed with a cold, when a beautiful girl with cat ears appeared by my side. She claimed that she was my pet cat, having transformed into a human...!? The cat usually acts cool, but the cat-girl is all dere-dere. A love story with a mysterious beauty. The popular YouTube video-manga with over 2.5 million views is serialized on the web!

(Source: Kadokawa, translated)