SECURE THE TREASURE

Metal boxes like that didn't exist in his world, and the only thing similar that existed in his world was a box made of wood that the people there usually used. In his world, it was more like a treasure box where people could store their valuables inside. It came in various sizes, and the sizes depended on the purposes the people had.

People in his world would keep their money or perhaps jewelry in the boxes, and to ensure that no one could steal those items from the boxes, they would place a padlock on them.

The lock needed a key to open it, which was why the people who owned the box needed to keep the key in a safe place so no one could find it. It was a bit of a pain when the people in his world even needed to think of where they could hide their keys, but the situation in this world was different because the metal box didn't have a lock, so there was no need for a key to open it.