Kim Dong Yi and Soo Min Rho, curious and mischievous Korean daughters of Morpheus, found a twin glistening poppy red-colored lockets poking out of the ground while on a certain quest. Attracted by the beauty of the two lockets, they took them and selfishly wore them without even asking or finding out who owned those. Unbeknownst to them, the two lockets belonged to Hypnos, their father’s father, who accidentally dropped them in the mortal world.
The lockets held overwhelming and supernatural power, and that anyone who wears it can enter the astral plane just by entering anything with a window, bring their physical body with them and bend the very plane to their will to a small extent, something that contradicts the real astral projection; but because of the power brought by the lockets, it was made possible.
Being so curious on trying out the lockets’ power, they decided to enter the astral plane via a large television set. Inside, the astral plane was a parallel world with ever-changing dream-like projections. Souls of those who can’t pass on and astral projections of living people roamed the astral plane. Being very mischievous and curious, they tried to possess the bodies of those they considered enemies, and caused trouble to the outside world without even causing their physical bodies to be harmed.
This greatly irritated Hypnos, as the two girls caused chaos in the astral plane because of their selfish deeds, disturbed his very domain, and the fact that they didn’t return the lockets upon finding them. Having enough of it all, Hypnos confronts them in the astral plane as they were about to possess another body. He demands them to give the lockets; they tried running away, but he stopped them with a flick of a finger. Hypnos was unstoppable in his domain, of course. In the end, Dong Yi and Soo Min gave back the lockets to Hypnos. As he kicks them out of the astral plane, he forewarns, “From this moment, I tell you, that in the future, your sons or daughters will suffer the consequences of what you did. You dare run away from my own domain? Fine then. Your own children will try to get away from me in the future, but I will not let them. I assure you that. Curiosity has a price, and you are paying for it.” With that, Hypnos disappeared, and the two were brought back to the real world.
After that confrontation, the two got into a fight. They blamed each other for picking up the lockets first, and in the end, their friendship was shattered, and they decided to quit camp, go back to South Korea and live their separate lives. Even before they left for their homeland, Hypnos has already made future arrangements; arrangements that will change the future of the two young ladies’ children.
So, Kim Dong Yi went back to her hometown, at Seoul, where her family owns a large kim chi restaurant chain. There, she was welcomed back by her mother and step father, Gun Woo Rho, a man who got engaged to her mother after her real father (Morpheus) left them all of a sudden right after they made love. Actually, her mother knew about her demigod identity, as Morpheus left her a note before he left, telling her to bring her to camp once she is attacked by any unusual monster she encountered. They kept this secret from the new head of the household, as he will only think that they are both crazy.
Shortly after her return, she took responsibility on helping her parents on the large family business. Shortly after that, she met Poseidon, the god of the seas and earthquakes. Well, you know what happened next. They fell in love with each other after Dong Yi served him with their famous kim chi, and hung out several times. From there, they made love, and eventually she gave birth to Jung-Hwa. He was treated very carefully and delicately as he grew up, but soon began to become rebellious after discovering new things when he went to school.
He's a son of Poseidon, a child of the Big Three, so monster attacks came to him earlier, at the age of twelve. Dong Yi, however, made safety precautions, as she herself, is a demigod. She hired an undercover satyr who disguised as a butler to keep Jung-Hwa safe and protected from any harm. So with the monster attack trying to obliterate him, the satyr came to the rescue. When Jung-Hwa awakened to his senses after passing out during the attack, he began asking questions on what he saw. Dong Yi told him that its was just some trick of his own sight, and told him not to worry because his butler will always be there for him to rescue him.
These attack occurred several times, with twice attacks each year. The satyr butler never missed a chance in protecting him, and Jung-Hwa was saved from harm's way. Every year, he began to be more puzzled on what is happening, but Dong Yi just kept on using the same excuse. However, during his latest attack, the satyr was defeated and died from the wounds he obtained. Jung-Hwa immediately ran for it like they always did, while honoring his "butler" who saved him many times before.
Every time he reaches a new age, Hypnos' "time bomb" decreased, which meant that his punishment for his half-granddaughters' bad deeds drew nearer. And at the dawn of his and Jin-Ho (Soo Min's son)'s 17th birthday, the "time bomb" "exploded". The special gift Hypnos imbued within the two children sparked to life, and they suddenly entered the astral plane. As if on a trance, they journeyed across the astrally parallel South Korea, with Hypnos on total control. In a matter of time even before they wake up, they astral possessed the other's body: Jung-Hwa possessing Jin-Ho's body and vice versa. As if like a switch, Hypnos turned off his special gift, locking them permanently in the body of the other.
The very next day, Jung-Hwa woke up with a yell. He was NOT in his body. Everything physically on him was changed all of a sudden. He didn't know where he was, or who the people are around him, why is he in such a shabby and low-living house, and certainly why the heck did he change into some other person's appearance. When this was found out by the other members of the family, they thought their "Jin-Ho" was cursed or possessed or something. Suddenly, her old friend, Soo Min, called. She reminded her of Hypnos' warning back then, realized it all good, and they decided to meet up to try and resolve the issue secretly. They tried pleading to Hypnos via dreams, but he never answered their voices of help. Eventually, they decided to bring their children to that one place, in hopes of their children themselves solving the crisis they are facing: Camp Half-Blood.
They first oriented them with everything regarding the Greek gods and all that, and they let them take it all in before sending them to Camp, as to prevent confusion. They didn't tell them about Hypnos' punishment, for the meantime, to make them accustomed to their new bodies. A week later, they brought them to New York City and into Camp Half-Blood, where they bid them goodbye and left.
As of now, Jin-Ho (now Jung-Hwa) and Jung-Hwa (now Jin-Ho) try their best to be together all the time, while getting used to their switched bodies and at the same time, being ignorant to how and why this unusual event happened to them. As for being claimed, Jin-Ho was claimed as son of Notus, and Jung-Hwa as son of Poseidon, despite of having some trouble with the two of them.