Apply for China Tourist Visa from Japan

Dear All,

I hope you are in best condition of health.
I am from Pakistan and studying doctoral course at University of Tokyo, Japan and I want to visit China as a tourist. I have a air ticket, invitation letter from my friend in China and all other documents. As i am a student and I want to save money. According to Chinese Embassy Rules for Visiting china by a foreigner as a tourist, can I directly go to Chinese Visa Center in Japan for applying for a tourist visa OR i must apply through some travel agent or a tourist company ?

Your sincere advise is needed.
Looking forward to hear from you.