When Jin was almost five, the nice lady next door gave birth to a baby boy.
The baby was her second son, having given birth to her first two years before when Jin was almost three.
When the baby was one month old, Jin's mother brought Jin and his elder brother over to say hello to the baby, and give both mother and baby several full moon gifts to celebrate the milestone.
Jin took one look at the baby, and promptly fell in love with the precious thing.
He made a promise to the baby that he would always love and protect him.
The baby's name was Jungkook.