i want to extend my visa period

hi, i would like to exted my visa period, because in my country they gave me 1 month of visa to be here so i would like to extend it to 3 or 6 months, by the way i am from venezuela so i really need to extend that period, thanks

You can go to an immigration office and apply for an extension of stay. You need a good reason for your request to be granted.

Location of immigration offices:
http://www.immi-moj.go.jp/english/soshiki/index.html

About the process:
http://www.immi-moj.go.jp/english/tetuduki/kanri/shyorui/03....