Tunnel Treasure Chest

 is a weapon in SINoALICE.

Weapon Story
Long ago, there were two brothers whose strength was known far and wide. They heard rumors of a treasure that could help them save their sick mother, and so they put together a crew and traveled to a cave in hopes of finding it.

Many trials awaited them. One after another, their companions died. Only the two brothers managed to make it to the deepest depths of the cave and find the treasure. Full of hope, they opened the chest. While skilled, they were new to adventuring and didn't take the proper precautions before opening it...

The older brother suddenly burst out in laughter. By the time the younger brother realized something was wrong, it was already too late. He shook his older brother violently, but the laughter continued. The younger brother smelled a stench coming from within the chest, and ran away in terror.

In his hasty retreat, the younger brother slipped and fell in some mud. The next thing he knew, his hand was drenched in blood. His life was over. It's been said that he now haunts the cave as a ghost, warning adventurers "not to open the treasure chest inside."