The Japanese Embassy in Berlin protested Saturday a major German daily's publication of a picture lampooning the Crown Prince.

Sueddeutsche Zeitung posted the picture Friday, the Crown Prince's 41st birthday, on the cover of its free magazine insert Sueddeutsche Zeitung Magazin.

In the color photo of the Crown Prince and Crown Princess was the German slang "tote hose" (dead trousers), meaning "nothing happens" or "impotent." The words were printed with yellow letters on the prince's trousers.

The caption read: "The oldest monarchy in the world is in crisis."

Japanese Ambassador Kunisada Kume said in a protest letter to the daily that the photo shows a lack of respect for the prince and "hurt Japanese people's feelings."

"I can't help being surprised that one of the high quality German papers behaved like this," he said.

The Imperial Household Law stipulates that only male descendants of the male line of the imperial family may become an emperor.

The Crown Prince, the eldest son of the Emperor and Empress is first in line to inherit the Chrysanthemum throne, followed by Prince Akishino, the only other son born to the Imperial Couple.

The Crown Prince and Princess remain childless.