Heart Corporation offer

Hi guys, hope someone can help me out.

So I got offered a contract by Heart and am set to depart to Japan shortly. I haven't already made plane bookings and so on and honestly, after all these negative comments I am highly skeptical. Also a lot of things aren't really clear on their side, which isn't helping my decision making easy at all. I feel really uneasy, I don't want to make a huge mistake.

I am currently unemployed in my home country but not really desperate, especially if I am going to be working for a garbage company.

What would your advise to me be?