City of Sin - Book 9, Chapter 127

Due to his own carelessness, Duanmu Huai finds himself transported into the world of the game “Star Ocean Online.” Starting from a humble core capsule, Duanmu Huai ventures across the starry sea to countless worlds. He awakens powers that have long been dormant, confronts threats lurking in the depths of the universe, and sets his sights on dominating the galaxy!

By the fourth year of Su Wan's career, every league rookie hears the same warning from their coach and veteran teammates: “You can try to impress him. You can even try to defend him. But no matter what—no matter if he hurls the most brutal insults your way—never, ever talk shit to him!”

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

A fluffy, sweet modern GL story about a mature older women and a cute university student.