Kyoukai Senjou no Horizon - Volume 1, Chapter 15: Gathered Friends in the Confined Room

The man forsaken by the world, the man a slave to money and the man known as the legendary God of War in the highly popular MMORPG Continent of Magic. With the coming of age, he decides to say goodbye, but the feeble attempt to earn a little something for his time and effort ripples into an effect none could ever have imagined.

The strongest man of the cultivation world, Yu Hua had sent the Grand Supreme Elderly Lord, Chi Hou to cultivate. After cultivating, Chi Hou was unrivaled for hundreds of thousands of years. However, he was ridiculed by the Demon Lord to be a bachelor who is as old as bone ashes and a fossil grade single dog. Not to even mention a girl, he doesn’t even have a little sister. In order to reverse the game, Chi Hou decided to kidnap the Demon Lord’s precious sister and turn her into his own little sister. He’ll first save her, then raise her, teach her magic, feed her dinner, tell her bedtime stories, and give her rare treasures. Like this, he’ll be the perfect brother. She won’t even remember her real brother.

Little sister: “What does this pervert who pulls me up every night to tell me ghost stories want to do? Cultivating to become a celestial is too hard, I want to go back to Earth!”

- Description from Novelupdates

My old man pointed to the flower-like woman and said, "Call her mother from now on." He then pointed to a flower-bud-like girl and said, "This is your little sister."

High bun, eyeglasses, long sleeve shirt and plaited skirt. Dressed so strictly, FengJiu reached 28 without having any intimate interaction with men.