The Delinquent Shimizu-san Sitting Next to Me Has Dyed Her Hair Black - Chapter 7Volume 3 .1 - Shimizu-san and the Summer Festival

Everything was going so well. It was the perfect path toward greatness.

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

To correct the mistakes of his past, a young man is forced to narrow the space between science and witchcraft, as he ventures on a quest to save his world from complete destruction.