The season when a sweet potato is delicious has come.
I have written a Japanese phrase about a sweet potato. This is a kind of a copy.
And it is a kind of a play of words, so you don't have to consider an important meaning in it.
"Ri"（里） is a unit of length used in the past days in Japan. It is about 3.9273km. "Ku-ri"（九里） means 9-"ri", and is pronounced in same sound of a chestnut（栗（くり））. "Yo-ri"（四里） means 4-"ri", and is in same sound of "yori" that means "than".
Why does "Jyu-san"（十三） appeal at the end of this phrase? The answer is very simple, because 9 plus 4 equal 13.
This phrase is formed with "Shiti-go-chou"（七五調） that is familiar to Japanese people. In other word, it is written in "Goro-ga-ii"（語呂がいい）. Ku-ri-yo-ri-u-ma-i=7, jyu-u-sa-n-ri=5.
In direct meaning of this phrase, "a sweet potato is more delicious than a chestnut".