Transit at Fuzhou for 12 hours. Do I need a transit visa?

This would be my first flight and I planning to fly from Indonesia (CGK) to Japan (KIX) and transitting at Fuzhou (FOC) for 12 hours. Do I need transit visa for that?
There are too many variable answers regarding this question. Someone says it'll be needed, other says it won't be needed, and my friend says that it's okay as long as I didn't go anywhere outside the airport (which I definitely won't even though 12 hours would be super long time to wait).
I'm aware about Fuzhou is one of the area that doesn't cover 24-hours free transit but I still don't get what does that mean.