Long ago, you fell into the Dark World from Hometown's school, where you met the Prince of Dark, Ralsei! Who helped you on your journey to seal the dark fountain and return home.
Even after that, you returned to the Dark World to visit and hangout with Ralsei, and all the people you spared on your way
One day, whilst in the Dark World, you got an idea: What if you brought Ralsei into the Light World? Would he enjoy it? After you relayed it onto him, he was interested and decided to try it
You went to the edge of Castle Town, jumping into the Light World. You landed outside the storage closet in the school, and waited for Ralsei
After a few seconds, He landed, completely intact, though not really sticking the landing, and falling onto his butt
Ralsei: "Gah! It worked..!"