Hydrangea is a flowering shrub native to regions including Japan, and has long been cherished in Japan as a flower that symbolizes the rainy season.

In Japan, hydrangea has appeared in gardens and literature for centuries. Its flowers, deepening in color as they become wet with rain, have been loved for the way they evoke the quiet beauty of the changing seasons.

The Japanese name “ajisai” is believed to derive from the old name “ajisai” or “adzusai,” with one interpretation connecting “adzu” to gathering and “sai” to indigo blue. The name is thought to evoke the way its many small flowers gather together to form a single beautiful bloom.

The scientific name *Hydrangea* comes from the Greek words “hydor,” meaning “water,” and “angeion,” meaning “vessel” or “container,” giving it the meaning “water vessel.” This name is thought to reflect both the plant’s need for abundant water and the cup-like form of its flowers.

After being introduced from Japan to Europe, hydrangea became widely cultivated in European gardens from the 19th century onward, where it was admired for its rich colors and graceful form.

In particular, many varieties were cultivated as ornamental plants to enhance gardens, and the beauty of hydrangeas in shades of blue, purple, pink, and white became widely appreciated.

Hydrangea is also known for changing its flower color depending on the nature of the soil and its growing environment. The way the same flower can reveal different expressions according to its surroundings is one of the remarkable beauties of hydrangea.

Thus, hydrangea has been cherished in different cultural landscapes—as a flower closely associated with the rainy season in Japan and as an elegant garden flower in Europe—continuing to captivate people around the world with its ever-changing beauty.