Experts are warning about what is known as "June syndrome," or mental and physical distress due to accumulated fatigue over the two months since the beginning of April, when many people in Japan start new jobs or schools.

For children, the stress from environmental changes after entering new schools or moving up a grade may lead to their refusal to attend lessons. Experts are calling on people not to miss children's signs of trouble, especially as they get more prone to suffer autonomic imbalance during the rainy season that tends to begin in June.

Much like the better-known May syndrome, or May blues, June syndrome is a general term for mental and physical disorders and is medically classified as adjustment disorder. Common symptoms include inability to get up in the morning, insomnia, headaches, abdominal pain, dizziness, nausea, malaise and loss of appetite.