Two tales are often told about Japan. The first is of a nation in decline, with a shrinking and ageing population, sapped of its vitality. The second is of an alluring, hyper-functional, somewhat eccentric society—a nice place to eat sushi or explore strange subcultures, but of little wider relevance to the outside world. Both tales lead people to dismiss Japan. That is a mistake.
I've found a meaning that says "characterized by excessive activity". But It seems unfit in this context.