What's this language?

Looks like Japanese to me, but, sadly, I don't know Kanji =)

Probably Japanese. The 1st three characters might be 木目オ. The rest is too blurry so I can't tell, maybe someone else can.

Edit: Actually the 1st character seems to have a line above itself, like this 术 character. As far as I know, there's no character like that in Japanese (unless there are two lines instead of one). Also I don't know whether the line next to the 3rd character connects or it's there on its own. So if it's chinese, then it might be
术目木1210; which doesn't make any sense.

It's a bit hard to read, but it does look like japanese.
The first two kanjis look like (edited, my japanese is getting super rusty), third one looks like a katakana for "o" followed by a strip and.. is that a latin 12 number?

It probably says something like "You gonna die in 12 days". Japanese stuff, just be careful with old vhs you may find around.

well..can you get all the characters in the photo?? only a part of the message is showed...

And is Japanese or Chinese, they use the same kanjis, if there´s no katakana or hiragana present is high probability Chinese.

(sorry if I have some gramatical errors)

This. For Sure. Seems veeery legit. And it kind of connects to what Ossos said :)

My drawing skills are bad and the only thing that I have in common with Japan is anime, so don't be mad at me. ;d

Either Chinese or Japanese.

It's Japanese, it says "The bag is treated with toxic chemicals, handle with caution, wear a hazmat suit at all times".

is katakana japanese for sure.

A cursed bag, its owner dies some horrible bag involving death and then it mails itself to another victim who's expected to meet the same fate unless they mail it first to a random person so that it becomes their problem.

It's Japanese and it says "We are sorry, the mysterious cursed video tape appears to be missing. Please die of your own accord within 12 days to avoid a lengthy reclamation process."

The chinese characters meant July, 11 (it got shipped on july 12 so it's probably the production or processing date). 1210 is the serial number,production number or something like that.
I don't know if it's correct, but that's what someone that seems to understand a little bit of chinese told me.