Just as Japan's growth engine is accelerating, it is emitting disturbing sounds. This week investigators raided Livedoor, the acquisitive internet group, over possible financial irregularities. Two days later, the Tokyo Stock Exchange had to close early after surging orders overwhelmed its systems.

The events have shattered the once-staid facade of corporate Japan. They suggest that while the economy is returning to normal, below the surface it is far from business as usual. What is less clear is whether what is going on is simply the country adjusting to unfamiliar challenges, or betokens structural problems that could hold it back.