There's a legend in Little Gui's homeworld: Whoever pulls out the sword in the stone would be the great hero foretold in prophecies.
However, no one ever managed to pull it out, and few even tried — because that was a historical relic. You'd get jailed for damaging it.

"I regret it so much right now... I was just feeling impulsive at that moment and wanted to show off to my friends. That's why I went to pull out the sword. I hope everyone can learn from my mistake..."