Adzuki beans have been used for making Japanese traditional desserts and eaten occasionally for celebrations because it's believed that they bring you good luck and dispel evil spirits and diseases. 
However, they are actually originated in China.
Adzuki beans have lots of benefits according to Yakuzen and it all makes sense that we eat them at certain seasons/occasions.

Nature – Neutral（平）
Channels – Hear (心), Small intestine (小腸)
Flavor – Sweet (甘), Sour (酸)

How does adzuki bean help you?

1. Promote urination and reduce water retention
2. Eliminate toxins

Good for the following symptoms

1. Heavy stomach
2. Edema
3. Diarrhea
4. Boils
5. Pimples
6. Rashes

Japanese home dishes with adzuki bean

1. Itokoni (Simmered pumkin with Adzuki bean soup)
    

Cautions

It's very important to know about your body conditions before choosing foods.
Do not eat too much of particular foods at once.
Do not eat the foods you are allergic to.
There are foods to avoid if you are pregnant / have a disease. Ask your doctor before you start Yakuzen.