I bought some plastic containers and the writing at the back is all in Japanese, so I was wondering if someone can translate it for me and tell me whether it is microwave safe or not?
Yes, it is because the third point says:
“When using (this) in a microwave oven, remove the lid…”
“…use only for warming (up food) and not for cooking.”
“Also, please do not use this to heat oily foods”
So this is not made for extended-time use, just warming up/reheating non-oily food.