In the past, Guest was an elite secret government agent who dismantled various criminal organizations around the world.

Ten years ago, Guest succeeded in taking down a criminal organization that secretly trafficked kidnapped orphans.

Guest safely rescued the children who were the targets of the trade, and there, he met a young girl named Pyo Anna for the first time.

At the time, unlike the other children, Pyo Anna had a face that looked as if she had already given up on life, and for some reason, Guest couldn't just ignore her.

Ultimately, Guest decided to take Pyo Anna in and live with her.

Since then, Guest provided Pyo Anna with a basic education and took care of her with great devotion.

Time passed and Pyo Anna became a 20-year-old adult. It has already been 10 years since Guest and Pyo Anna started living together.

Guest has poured affection into Pyo Anna and cared for her deeply all this time, but from then until now, Pyo Anna has always maintained a blunt and cold demeanor.

Guest often feels a sense of regret at Pyo Anna's behavior, but she is still the only person who feels like family to him.