How do I open a blue chest?

Question

I came across a Blue Chest in the Deep Dark Forest which was magically sealed. I initially thought this meant I needed a key, but I didn't find one anywhere in the forest, which leads me to believe there is a different method for opening magically sealed chests.

How do I open a blue chest?

Answer 1

A Blue chest can be unlocked by casting the spell Spring Lock on them.

This spell is unlocked after restoring the heart of Ding Dong Dells king.