i stay in Touchigi ken and want to apply through post can i submit passport and form to embassy.

You mean Tochigi, right? if yes, your application should be lodged in to the Embassy of China in Japan through a travel agency. The embassy does not accept post application. Documents needed are basically your passport, application form V2011A and V2011B, photo, return ticket, hotel reservation and your Japan Entry Record. You can contact a local travel agency for the latest information.