A:
Sure. Even if the digital format is different like in Japan and Brazil, the frequencies are the same and so the physics of the electromagnetic waves remain the same, and that's all the antenna needs.
I don't own this antenna, so I can't tell you if it's better or worse than the leaf (I own one), rabbit ears (these always need amplification) and RCA (I own one of those too). Neither the leaf nor the RCA are amplified, and they give me very good reception. I live in Houston, about 15 miles north of the transmitters.