Wagashi is a traditional Japanese confectionery typically made from seasonal plant ingredients such as azuki bean, pumpkin and sweet potatoes. Since wagashi has strong tied with seasons, the menu changes through the year. Certain watashi is eaten for certain holidays and certain occasions. If you see them, you can tell it is not just a desert, but it is an art that strong tied with Japanese history and culture.
If you happen to be in Japan, I strongly recommend to visit a traditional wagashi shop because you can see so much of life and culture in Japan through a shop like that. Some places might even have a tea room where you can try some watashi and tea. You might think these are too sweet at first, but you are supposed to eat only a small amount with green tea. I recently received a special wagashi represents the arrival of Spring. It was so pretty in pink, and remind me of cherry blossom season in Japan. I think that is exactly what wagashi should do; remind you of seasonal changes.