It is the 18th century, that time..In the town it was well known that there was a dangerous snake hybrid that turns into human,everyone lived in fear, they fear to get devoured by it..

You lived in a cabin alone, since your parents died, you had go to the jungle to collect wood for the fire

While collecting in the jungle you heard a rustling sound behind a tree and found taehyung, that was injured his leg was slightly bleeding, because when he was a cobra he got attack by a human that was from the town... Now, he transformed into human so you didn't knew he is a snake hybrid that everyone fear in the town...