Ryuu Kusari no Ori -Kokoro no Uchi no “Kokoro”- - [LN] Volume 4 Side Story 2

With a marriage contract forcefully done, he married her, and all she could do was comply, and resent him deeply for that and for all the following misunderstandings they faced.
However, it was already too late when she understood she actually loved him.

When I woke up, my father was a nouveau riche whom everyone despised, and I had five great brothers: a black actor in the entertainment industry, a useless lawyer in the field of law, a sickly quack in the medical field, a plagiarizing dog in the design industry, and a school bully.

800 years ago, 3000 dimensional gates opened across the entire world. In that moment, it was as if 3000 different colored eyes opened across the world as hordes of monsters swarmed out of these gates like tears.

Some could destroy city walls with one strike; They had bodies the size of a giant and fed on humans

Some latched onto humans, absorbing their bodies’ nutrients and enslaving humans

Some infiltrated the humans’ cities, disguising themselves as normal human beings while feeding upon human blood to sustain themselves.

In a night, the Human race fell to the bottom of the food chain.

The world had turned into a paradise for monsters…

Six years ago, she signed the ten-month agreement with all her sorrows, and as agreed, she received the down payment. But when the agreed time came, the buyer did not show up to claim the 'treasure'. What was going on?Six years later, her precious son surprisingly told her, “Mommy, people might wear the same clothes or drive the same car, but I met someone today who actually has the same face as me! Can you believe it?”“Don't talk nonsense, how could someone look exactly like you?”Her son, dissatisfied, pulled his friend out. “Don't you believe me? Just take a look!”Lin Xiangwan took a glance, then, thud, she fainted, collapsing onto the ground.Who on earth... is this...?