The Japanese people eat rice cakes or mochi on New Year’s holidays.
One day, some Rakugo performers got together at their mentor’s house and they were talking about why rice cakes easily go moldy.
But nobody knew why.
Their mentor was disappointed with them.
M: Nobody knows why rice cakes go moldy?
S: No, please let us know why.
M: You are so foolish. They go moldy because you don’t eat them soon after they are made.