Kujibiki Tokushou: Musou Hāremu ken - Chapter 20

However, he did not know that he was not raising just a harmless pet, but a biological weapon secretly made by the government… a real monster.

As a former librarian, Rand felt that he had been living an ordinary life, the one that he had reclaimed unconsciously every single day.

Recently, he has been a little upset because the pet fish he accidently brought home to raised seems to have undergo some strange changes

Well, it turned into a merman.

- Description from Novelupdates

Stranger Danger features an epic journey through a rich world fraught with dangers and uncertainty. Ye Qing would have to face down deadly Strangers who can be anything and everything in the world—an animal, a plant, a fog, or even the demon on your shoulder—and the deadlier threat known as humanity. Will he succumb? Or will he survive and even thrive in this dangerous yet beautiful world?

……………………………………………………………

Dear readers! Without any ads, maybe you will prefer .

Keith, a regular office worker from Earth, suddenly transmigrates to the world of the novel he had been reading for the past decade. The new world, which was also called Earth, was slightly different. People with various powers existed who were called awakeners, making this world comparatively dangerous and also mysterious. While he was thrown into the novel’s world, he was also given a mystical ability to grant systems to other people. Armed with his special ability, he slowly climbs up the power ladder by taking “taxes” from the people he would give systems to. The only question that remained, was what would a realistic normal man, when faced with a similar minded protagonist, do when their goals opposed each other.