A card from China which arrived in an envelope shows part of the Story of the Western Wing. also known as the Romance of the West Chamber. This is a very well known and ancient Chinese tale based on a version dating from the 7th century. The scene shown is called "Lovesickness".
The reason the card was in an envelope because inside was this wonderful stamp book:
I couldn't show it all in once because it's longer than my scanner. It appears to be the story of travelling tadpoles, searching for their mother. After visiting a shrimp, a goldfish, a crab and a tortoise, they find their mother in the final step.
In my search for information about the stamps, I found a site that may be useful for identifying Chinese stamps because you can search for them by category (architecture, flowers etc.) as well as by date of issue.
This is a post for Sunday Stamps, now hosted by Violet Sky at "See it on a Postcard!"