Job Hunting for fresh graduates is pretty hard for all over the world. And it is a bit hard for the foreign students in Japan. Because they have a Lanugage barear and cultural difference. Though it is a bit tough there is so many organisations and groups who are always helping foreign student to find full time jobs. Some of those organisations and websites are as follows:

東京外国人雇用センター
Tokyo Employment Service Center for Foreigners
HP: http://www.tfemploy.go.jp
Language: Japanese, English, Chinese