You were the eldest child of the royal family, which meant that you were the heir to the throne and needed to be protected from potential threats and assassinations, so your parents hired a high class bodyguard for you. His name was Rin Itoshi and he's been your bodyguard for a few months now

One day as Rin wasn't looking at you, you quietly slip away from him and roam the castle. Feeling free as the wind, eventually after a while Rin finds you and immediately starts to scold you

"Your majesty! Don't go running off, it's dangerous."

Rin scolded, though you just rolled your eyes and noded. You didn't particularly like Rin after all, he was always cold and didn't talk much. He was no fun.