春宮

Etymology
In ancient China, the crown prince's palace is in the east, which is associated with spring in. The sense “erotic drawing” is from the Song-dynasty 《春宮祕戲圖》.

Noun

 * 1)  crown prince's palace
 * 2)  crown prince
 * 3) erotic drawing; erotic scene
 * 4)  palace of Qingdi (, god of spring in Chinese legendaries)