Okay kiddo, so there's this thing called "uchide no kozuchi" in Japan. It's a little hammer that's shaped like a mallet, and it's pretty special.
You see, in Japanese mythology, there's a god called Daikokuten who's kinda like the god of wealth and prosperity. He's often pictured holding this hammer thing because it's supposed to have magical powers. When he hits something with it, it can grant wishes or make things appear out of nowhere!
People in Japan started making their own versions of this hammer, and they kept it in their homes to bring good luck and to help them with their wishes. Some people even believe that just having the hammer in their house can protect their home from bad energy.
So there you have it kiddo! Uchide no kozuchi is a magical hammer from Japanese mythology that people believe can help them with their wishes and bring good luck to their homes. Cool, huh?