er, as long as U's address is correctly stamped, you can usually send it. As for whether you can see it or not ... letter brokers who send it to IDOL have to open it first, and J's family stipulates that gifts are not allowed, so don't put extra things in the envelope. Actually, the language doesn't have to be Japanese, English or Chinese ... er, it's unrealistic for the time being ... but Japanese is the best (I've been bilingual in China and Japan before). ... and then the content ... if there is no inappropriate content (I don't need to give you an example), you can generally pass the translation ... Although there is online translation, the program is very well translated. OTZ can ask for help in Baidu knowing Japanese classification or go to some websites that provide manual translation.