Reading seems to be a very popular hobby in Japan, whether it’s manga, a novel or just the newspaper, it looks like the Japanese read all the time (except for the few who play games instead, but probably read at other times.)
So it is a natural thing to find many places that sell and buy books. Like this one I found when I went to visit the Shitennoji temple (The temple of the four kings.) Apparently, I found out later that this kind of used book sale is held regularly in the temple’s garden, but of course all of the books in Japanese, and although they are a bit yellowish at the sides they are in good condition.
Please note that I have tried not to take pictures with people in them, but there were a lot of people buying the books, that were as cheap as ¥100.