"At least I think it says IIC"

Yes, that's what I read too. I downloaded the datasheet (which is in English!) and verified that it does indeed use IIC and includes an English font. The instruction set looks very HD44780-like.

Interestingly, the first page of the datasheet lists "Brand: WINSTAR DISPLAY CORPORATION". I Goggled for that, but didn't follow the links too far. Looks like it may be worth digging into!