1, to apply for a Japanese tourist visa, you need to provide proof of work and property of both parents.
2. A deposit of 3-5W is required, which can be refunded after returning to China. There's no need to worry. The deposit is to prevent you from staying in Japan or not coming back. Both Korea and Japan need a deposit.
The passport is valid for at least half a year (the last page of the passport needs my signature).