The cultivars most familiar in East Asia have a uniform red color, but there are white, black, gray, and variously mottled varieties.

Evidence suggests that "wild azuki bean have been domesticated and cultivated in Japan for over 10,000 years".

[8] Separate cultivars with smaller seeds and higher biomass are bred for fodder production and as green manure.

However, in cultivated gardens the weed form is recognized as contamination and lowers the seed quality of adzuki cultivars.

[9] The bean is also grown commercially in the US, South America, India,[11] New Zealand, Congo, and Angola.

[9][11] Fertilizer application differs widely depending on expected yield but is generally similar to soybean.

Furthermore, pests such as the adzuki pod worm, Japanese butterbur borer, and cutworm attack the crop.

[9] The description of the adzuki bean can vary between authors because there are both wild[12] and cultivated forms[8] of the plant.

The adzuki bean is an annual,[9][12] rarely biennial[8] bushy erect or twining herb[9][12] usually between 30 and 90 centimetres (12 and 35 in) high.

[12] The adzuki bean has a taproot type of root system that can reach a depth of 40–50 centimetres (16–20 in) from the point of seed germination.

[13][14] The leaves of the adzuki bean are trifoliate, pinnate and arranged alternately along the stem on a long petiole.

[13][14] The thousand kernel weight is between 50 and 200 g.[8] There are many different seed colours from maroon to blue-black mottled with straw.

In particular, it is often boiled with sugar, producing red bean paste, a very common ingredient in all of these cuisines.

It serves as a filling in Japanese sweets such as anpan, dorayaki, imagawayaki, manjū, monaka, anmitsu, taiyaki, and daifuku.

A more liquid version, using adzuki beans boiled with sugar and a pinch of salt, produces a sweet dish called hong dou tang.

Some East Asian cultures enjoy red bean paste as a filling or topping for various kinds of waffles, pastries, baked buns, or biscuits.

Adzuki beans are commonly eaten sprouted or boiled in a hot, tea-like drink.

Traditionally in Japan, rice with adzuki beans (赤飯; sekihan) is cooked for auspicious occasions.

Cooked adzuki beans are 66% water, 25% carbohydrates, including 7% dietary fiber, 8% protein, and contain negligible fat (table).