The Least Useful Guide to Fukuoka

This is a torii gate placed at the entrance of a local shrine. As you can see, there are pebbles on the top of the gate.

These are not ‘official’ ornaments of the gate; someone must have attempted to put the pebbles there.

But how and why?

I haven’t tried this ritual myself, but I have seen some boys tried to do so and assumed they were just playing.

Some said that throwing stones onto the gate is considered a trial of one’s luck; If your stone successfully land on the top, your hope will be realised.

But now, it shouldn’t be recommended that way of testing how lucky you are. Most of shrine gates are very old and valuable. If you broke or made any chip in the gate, you would be charged a huge compensation, not to mention being cursed.
Also, you can’t get a stone to throw in the first place as most of roads are asphalted like mirror.

So where did these pebbles come from? Have they been staying on the top of the gate since when there were a plenty of pebbles around here, despite the fact that a big earthquake hit Fukuoka in 2005?