I'm going to stay in Asia for one year (6 months Japan and 6 months Korea)

and I want to travel around Asia as much as possible, so I would like to go to China for tourism. However I am a student, I have a job, so I only can visit during my holidays and the weekends, that why I wanted to have a Multi-Entry with 12-month Validity visa. What are the criteria for this type? Is my reason enough to get it, if I just pay? Should I show several flights tickets to show that I need a multi entry one? Do I have to prove that I will stay in Asia for a year, and do I have to prove that I am studying and working? Also I have a European passport so people told me it should be ok but I am not sure. Having this 1 year visa would make me save a lot of money. Thanks!