There was once a girl who fell in love with a monk.
Unfortunately, their love was forbidden by the temple and religious authorities as it is deem unholy and it may disrupt the monk from his Dhamma practices.
The monk was not allow to meet and talk to the girl within and outside the temple premises. The only close encounter they would ever get is when the monk goes for his usual bell duty outside of the temple.
With that, the girl would secretly hide love messages inside the bell everyday before the monk attend to his bell duty. In return, the monk would also reply to her messages by leaving notes inside the bell.
To protect the secret letters from being taken by thieves and the public, the monk cast a spell on the bell in which that whoever looks underneath the bell, the person will be cursed with an everlasting of misfortunes and bad luck for the rest of his life.