does this visa can be done personally or by mail?

Usually, the embassy of PRC doesn’t accept the application by mail. You can submit it by yourself, or you can entrust someone or agency to do it for you. Those documents are required which include your passport and copy of its data page, the application form with a recently-taken passport-style photo glued, your residence permit in Japan, proof of your financial support, as well as round trip air tickets and hotel reservation.
According to the notice from the consulate general of PRC in Japan, you’d better find a designated agency to apply for it fro you because many people may go there and you have to wait for a long time.