Maou-sama no Machizukuri! ~Saikyou no Danjon wa Kindai Toshi~ - Volume 1 Chapter 15

The 7-year-old little crybaby met 11-year-old big brother who ran away from home.
[This man became the protector of redemption in his life]

The 16-year-old little dragon fell in love with a 20-year-old big brother.
[It’s a pity that the big brother didn’t recognize him as the little crybaby]

The 23-year-old single father and 27-year-old chief executive meets again.
[This time the little crybaby and his big brother are finally together]

Fortunately we met through hundreds of millions of people, Thank God, for letting us break through many obstacles and get back together again, falling in love with you and being with you again is the greatest fortune in my life.

- Description from Novelupdates

Being a nobody from a poor district of the Federation, Nick is a sixteen year old boy just trying to find his place in the world. When he finally gets his shot to enter the Beast Domain upon turning sixteen, he jumps at the opportunity to finally make something of himself — to carve out his own future.His goal? Survive. Hunt. Earn enough money to finally support his little sister back home and bring them out of poverty.But to a naïve young boy like Nick, the world is far more sinister than it seems — leaving him no choice but to adapt or die.To a poor young man like Nick, though, there was only one choice he could make.Follow Nick as he navigates these obstacles and carves out a future for himself and his sister, all while uncovering the various mysteries that shroud his worldview in darkness.

After three years of struggling in the big city, Chu Zhishui finally managed to save enough money to buy a home. However, she discovered that she was the only human in her new workplace?Chu Zhishui: Are even supernatural creatures seeking stable jobs with iron rice bowls now?–In the office, Chu Zhishui gradually adapted to working at the supernatural bureau. Despite her diligence and dedication, she couldn’t escape the gossip and social niceties of a small town, facing the enthusiastic attention of the matchmaking department head.Supernatural Department Head: “Little Chu, you’re doing so well at work. Have you considered settling down and starting a family? Let me set you up with someone. Do you have any requirements?”Chu Zhishui silently recited the mantra of singlehood in her mind, but not wanting to dampen the mood, she decided to be deliberately demanding: “I don’t ask for much in a partner. Just someone good-looking, filial to my parents, capable of doing housework, and able to earn money to support the family…”The supernatural department head replied readily: “Great, I’ll find someone for you!”Chu Zhishui steeled herself and added with gritted teeth: “…and they must be able to bear children!”Just as she thought the department head would give up, the other party had a sudden realization: “The one in your office can bear children! Why don’t you just admit you like him?”Chu Zhishui: ???–Chu Zhishui: I thought I could slack off at my job in the supernatural bureau, but it turns out that was just wishful thinking.

On her wedding day, she was humiliated; her status as the legitimate wife was instantly changed into that of a concubine.