Details about getting a visa

Hello! I'm an American passport holder living and working in Japan, but not in Tokyo--I live several hours away by train. I'm visiting China next month and need to get my tourist visa L from the embassy in Tokyo. I'm wondering, after going down to Tokyo to apply for it at the embassy, is it possible to schedule a date it up? For example, I'm thinking of applying on Nov. 26, but I was thinking of picking it up the next time I can get to Tokyo easily, which would be Dec. 21, obviously much later. Is this possible? Is there any way to simply have it mailed???

Also, I'm finding a lot of mixed information about applying for it--MANY bloggers on the 'Net (holding passports from various countries, including the U.S.) have shared their accounts of applying for (and getting) tourist L from the embassy in person, NOT through a travel agency. Is it possible to simply go to the embassy to apply for it, or do non-Japanese citizens have to apply through a 3rd party?