Dutch media have reported a rare private trip to the Netherlands by Crown Prince Naruhito and his family -- and Japanese reporters who converged in the country to cover the visit -- with a sense of curiosity.

In its electronic edition Thursday, Trouw, a Christian-leaning Dutch newspaper, said an official reason for Crown Princess Masako's trip to the Netherlands is to convalesce, but the visit is more likely to be "an escape."

The paper said the 42-year-old Crown Princess has been under pressure due to the need to give birth to a male, who would be next in line to the throne after Crown Prince Naruhito, but they have only a daughter, Princess Aiko.

Princess Aiko, 4, cannot become the reigning empress under the current male-only Imperial succession law.