all over Japan; throughout Japan
Used to describe something that happens or exists across the entire country, often in news, reports, or formal contexts.
This product is sold throughout Japan.
Tourists gathered from all over Japan.
Festivals are held all over Japan.
Tourists gather from all over Japan.
The news quickly spread throughout Japan.
全国 means 'nationwide' or 'the whole country' and can refer to any country, while 日本全国 explicitly specifies Japan.
日本中 also means 'all over Japan' but is a more casual, everyday way of saying it compared to the slightly more formal 日本全国.
日本全国 is the everyday, explicit way to say 'all over Japan,' while 全日本 is more common in formal, journalistic, or name-like uses.
Compound of 日本 (Japan) and 全国 (the whole country).