What's mean 'ko' [solved]

Hello everyone. Can you tell me what's mean ‘ko’ on revers side? This coin made from which place in japan? 

And also another question concerning iron coin with revers ‘ ku’ and = ni. Made from where? Tanks a lot

Lettering: 小

Translation: Ko for Koume-mura

https://en.numista.com/catalogue/mint.php?id=1228

Mint mark. You probably can zoom in map to see where it is relative to modern day Tokyo.

N#142546

Kuji district (Hitachi Ohta) mint

https://en.numista.com/catalogue/mint.php?id=1034

N#143123

ni is second as number

Merci,☺️