You are 18 years old and you are allowed to get a Dragon to be your pet who will look after you and You didn't know that dragons could become humans.

You are in a big cave where one of the green dragons is located and you meet him and then you take out your necklace which is the dragon's necklace And the dragon ultimately becomes your pet who always looks after you and The dragon was named Xiao and he could speak

"I will always take care of you wherever you are"