A Flower for the Rain: Hydrangeas and Siebold's Lost Love

Coloring Tokyo's Rainy Season

On a rainy June 19th, at the quiet Chokokuji Temple in Asakusa, Tokyo, clusters of potted hydrangeas were in full bloom. 

The temple grounds host a hydrangea market every year during this season, with colorful potted hydrangeas filling the space. Under the heavy, overcast skies of the rainy season (tsuyu), their vibrant blues and deep purples offer a striking contrast to the gray day.

After enjoying the hydrangeas at Chokokuji, I took a walk toward Sensoji. Along the way, I began noticing hydrangeas growing here and there—not in pots this time, but blooming from the ground along streets, in temple grounds, and in small corners of the neighborhood.

In Japan, this is the season when hydrangeas—known in Japanese as ajisai—quietly reclaim the corners of shrines, temples, streets, and parks, bringing a serene elegance to the early summer landscape.

Though the rain falls steadily, it is the perfect backdrop. The hydrangea is a flower born for the rain—a quintessential symbol of the season that brings a sense of calm to all who pass by.

A Mirror for the Human Heart

A hydrangea looks like a delicate floral pom-pom, but it is actually a cluster of tiny blossoms. One of its most fascinating traits is how it changes color—shifting between blue, purple, pink, and white depending on the acidity of the soil.

Native to East Asia, unique species of this flower have grown across the Japanese archipelago since ancient times. Its history in Japanese culture is profound; it appears in the Manyoshu (The Anthology of Ten Thousand Leaves), Japan's oldest collection of poetry, compiled roughly 1,200 years ago during the Nara period. Since then, ajisai has been a frequent muse for literature and art.

Because hydrangeas naturally shift their hues, historic poets often used the flower as a metaphor for the fickleness of human emotions. The changing petals came to reflect the transience of love, the fleeting nature of romance, and the bittersweet impermanence of life itself.

The Hydrangea and the Foreign Scholar

Philipp Franz von Siebold, sketched by a Japanese artist shortly after his arrival in Japan (1826). In addition to his likeness, handwritten notes record details of his clothing and physical features.

While the flower is deeply woven into Japan's ancient cultural fabric, few people know that its journey to the rest of the world is tied to a remarkable foreign scholar.

That man was Philipp Franz von Siebold, a German physician and naturalist. While his name might not be a household word in Europe today, in Japan, he is a famous historical figure featured in every school textbook. In 1823, during the Edo period, when Japan was strictly closed to the outside world under its isolationist policy (sakoku), Siebold arrived in Nagasaki as a doctor for the Dutch East India Company.

Siebold was a brilliant physician, but he was also driven by an insatiable intellectual curiosity. He opened a private academy called Narutaki-juku, where he taught the latest Western medical science to eager young Japanese students. His work left an indelible mark on the development of modern medicine in Japan.

Yet, his interests went far beyond medicine. Commissioned by the Dutch government to survey Japan's nature, culture, and geography, Siebold—with the help of his dedicated students—amassed a staggering collection of specimens and artifacts. He gathered plants, animals, clothing, crafts, and even the everyday household items of ordinary people.

The Woman Called "Otaksa"

In his personal life, Siebold built a family with a Japanese woman named Taki, and they were blessed with a daughter. In nineteenth-century Japan, it was common to address someone affectionately and respectfully by adding the polite prefix "O" and the honorific "san" to a name. Thus, Taki would naturally be called "O-Taki-san."

To Siebold's European ears, however, this expression sounded almost like a single name. He lovingly rendered it as "Otaksa"—a Westernized spelling that preserved the sound of the Japanese nickname he used for the woman he loved. Their daughter, Ine, would later make history as Japan's first female practitioner of Western medicine.

An Endless Curiosity and the "Siebold Incident"

However, Siebold's boundless quest for knowledge eventually took a tragic turn.

In 1828, just as he was preparing to sail back to Europe, authorities inspecting his cargo discovered highly detailed maps of Japan—which were strictly guarded state secrets at the time. The shogunate suspected him of espionage and subjected him to a harsh investigation.

Ultimately, the 33-year-old Siebold was sentenced to a severe punishment: permanent banishment from the country. His Japanese disciples were also heavily penalized. This historical drama became known as the "Siebold Incident." Forced to board a ship home, Siebold was torn away from his wife and his newborn daughter.

Back in Europe, Siebold eventually started a new family, but he never stopped studying Japan. He published extensively, becoming recognized as Europe's leading authority on Japanology.

Remarkably, his story did not end there. About thirty years later, after Japan finally opened its borders to the world, his banishment was lifted. At sixty-three years old, Siebold set foot in Nagasaki once again and was finally reunited with his Japanese family. He spent his remaining years in the country serving as an important diplomatic advisor.

"Otaksa": A Love Story Etched in Petals

Though he had been abruptly exiled, Siebold had managed to bring a massive collection of Japanese botanical specimens back to Europe. Among them was the Japanese hydrangea.

In his monumental botanical work, Flora Japonica, he officially documented a particularly beautiful variety of the flower, giving it a scientific name:

Hydrangea otaksa

Otaksa. It was the name of his beloved Taki, the woman he had been forced to leave behind on the other side of the world.

Before long, this mysterious Eastern flower captured the hearts of European gardeners. Modified and bred into larger, showier blooms, it became a massive commercial success across Europe—carrying the scholar's memory of his lost love within its scientific name.

Fascinatingly, most of the large, ornamental hydrangeas planted across Japan today are actually these "Western hydrangeas" that were imported back into the country. In a poetic sense, the flowers traveled across the globe only to return home to Japan, carrying Siebold's devotion back with them.

Pausing by the Hydrangeas

Today, we take for granted the vibrant hydrangeas that decorate our rainy season.

But the next time you walk past these blossoms heavy with raindrops, take a moment to look closer. You might just feel the overlap of two completely different histories: the ancient Japanese landscapes loved by the poets of the Manyoshu 1,200 years ago, and the unforgettable romantic legacy of a foreign scholar who loved Japan so deeply that it cost him his home.