Why a dragon god at a Buddhist temple? The mystery of Zenpoji (Tsuruoka) and its sea-guarding dragon faith

Tsuruoka's Zenpoji, revered by fishing communities across Japan — and the wonder of Japan's dragon-god faith

Zenpoji (Zenpō-ji) sits in Tsuruoka City, Yamagata Prefecture.

From the name alone, you might picture just another old, storied temple.

But Zenpoji has a slightly curious feature.

It is a temple of dragon-god faith.

And that faith reaches far beyond the local area. Zenpoji has long been known as a temple revered by people whose lives are tied to the sea — fishermen and shipping workers who pray for safe voyages and bountiful catches.

Which raises a question.

Why would a Buddhist temple honor a dragon god?

Many people imagine a dragon god (ryujin) as a “deity” enshrined at a Shinto shrine. But look closer, and the story isn't so simple.

In fact, dragons and dragon kings appear in Buddhism from ancient times, too. And the Buddhist dragon-king faith that reached Japan overlapped with long-standing local beliefs in water and sea deities, with rain-praying, farming, fishing, and prayers for safe voyages — taking on different forms in each region as it was handed down.

To understand Zenpoji's dragon-god faith is to glimpse how the Japanese have viewed nature, how they have made sense of gods and buddhas, and what the people who live by the sea have prayed for.

Zenpoji: a place of prayer for those who live by the sea

When you think about Zenpoji's faith, the first thing you can't leave out is the sea.

Tsuruoka lies in the Shonai region, facing the Sea of Japan. For fishermen and sailors of old, the sea was what put food on the table. A good catch meant they could feed their families. A boat returning safely meant another day's work tomorrow. The sea sustained people's lives.

But at the same time, the sea was terrifying. Sudden storms, strong winds, high waves, thick fog. In an age without precise weather forecasts or GPS, simply going out to sea meant risking your life.

And so people prayed.

“Please let us return safely.”
“Let the sea be calm again today.”
“Let the catch be plentiful.”

Once you understand that Zenpoji's dragon-god faith is bound up with these urgent wishes of the sea's people, its weight comes into view.

It was less about “visiting for good fortune” than about praying to come home alive.

What exactly is a “dragon god”?

In Japan, dragons have long been imagined as beings that govern water. Rain, rivers, ponds, lakes, the sea. Water is essential to human life.

Without rain, crops won't grow. Without water drawn from rivers, fields go dry. From the sea come fish. Water, in other words, nurtures life.

Yet when water turns violent — floods, towering waves — it reveals a terror beyond any human power to control.

Water holds both blessing and dread. The dragon, too, has been worshipped as a symbol of both.

It brings blessings. It brings rain. It guards the water. And at the same time it is tied to the raging power of nature. That is why people have feared, revered, and prayed to the dragon.

In fact, Buddhism has dragons too

When people hear “dragon god,” many picture a Japanese deity, or perhaps a Chinese dragon.

But in truth, dragon-like beings appear in Buddhist scriptures and traditions from very early on. One of their sources is said to be the Naga of ancient India.

The Naga was known from ancient times in India's religious culture as a serpent- or dragon-like spiritual being — associated with water and rain, the underworld, treasure, and abundance.

As Buddhism took shape, the Naga was drawn into the Buddhist world as well: appearing as a protector of the Dharma, as a guardian of the Buddha's teachings, and as a being connected with water and rain.

So a “dragon-like being” is by no means unrelated to Buddhism.

In China, the Naga came to be understood as the “dragon” and “dragon king”

When Buddhism passed from India to China, the Naga came to be understood by overlapping it with China's own ancient image of the “dragon.”

In China, too, the dragon was thought of as a powerful spiritual being governing water and rain. The Buddhist Naga merged with it, and in Chinese translations of the scriptures it was rendered as “dragon” (ryu) or “dragon king” (ryuo).

And when Buddhism reached Japan by way of China, dragons and dragon kings came with it.

Broadly speaking, there is a long flow: the Naga of ancient India → the dragon king fused with China's dragon culture → the dragon king in Japanese Buddhism.

Buddhism also has the “Eight Great Dragon Kings”

One well-known group of dragon kings in Buddhism is the Eight Great Dragon Kings (Hachidai Ryuo). Dragon kings appear in Buddhist scriptures such as the Lotus Sutra, positioned as protectors of the Dharma.

In Japan, dragon kings came to be worshipped in connection with rain-praying, the guarding of water, prayers for good harvests, and protection from drowning.

In Esoteric Buddhism especially, dragon kings played an important role in prayers concerning water and rain; in the Heian period there are even cases of the imperial court ordering monks to perform rain-praying rituals.

In other words, prayer to the dragon kings was not merely folklore or popular legend — at times it appeared within state religious ceremony.

The dragon king Zennyo Ryuo

One notable figure in Japan's dragon-king faith is Zennyo Ryuo.

Zennyo Ryuo is spoken of as a dragon king who brings rain, and is known within Esoteric Buddhism and rain-praying traditions.

What this tells us is that, within Buddhism, the dragon king was received as a being deeply tied to water and rain from very early on.

So was “dragon-king faith” something nationwide?

Here a little care is needed.

Hearing the phrase “dragon-king faith,” you might feel as though there were a single nationwide religion or sect. But that is not the case.

It's easier to think of it this way: there was no monolithic “dragon-king religion” spread across the whole country. Rather, there was a tradition of worshipping dragon kings within Buddhism, and it took on its own form in each locale as it joined with local water-deity beliefs, rain-praying, farming, sea-deity beliefs, fishing, and prayers for safe voyages.

So it is a faith seen nationwide, yet nowhere in quite the same form. That is what makes Japan's dragon-king and dragon-god faith so interesting.

Japan had “water gods” before Buddhism arrived

And here is something even more important.

Japan had beliefs about water and the sea before Buddhism ever arrived. Rivers, waterfalls, ponds, springs, the sea — such watery places were thought to hold sacred power.

For those who farm, whether it rains is a matter of survival. For fishermen, whether the sea turns rough is a matter of life and death.

So even before Buddhism came, the Japanese received water not as a mere natural phenomenon but as something to be feared and revered.

Into this came the Buddhist dragon-king faith. Japan's ancient water-deity beliefs and Buddhism's dragon-king faith shared common ground — water — that made them easy to overlap.

Seen through shinbutsu-shugo, dragon-god faith gets even more interesting

Here we come to shinbutsu-shugo — the syncretic fusion of Shinto gods and Buddhism.

Today we tend to divide things up: “shrines are Shinto, temples are Buddhism.” But in old Japan, gods and buddhas were not separated as sharply as they are now.

Over a long time, Japan's ancient gods and the buddhas brought from abroad became intertwined, and ideas spread such as “perhaps this god is a buddha appearing in another form.”

A temple within a shrine's grounds; a god enshrined within a temple; prayers offered to both gods and buddhas. This long history is generally called shinbutsu-shugo.

By modern instinct, you want to ask, “So which is it — a god or a buddha?” But for people back then, drawing that line strictly may have mattered less than the fact that the being protected their daily lives.

Where the Buddhist dragon meets Japan's water and sea faith

Seen this way, the fact that “Zenpoji is a temple, yet worships a dragon god” starts to feel not so strange after all.

Buddhism had its own dragon and dragon-king faith from the start; Japan had ancient beliefs in water and sea deities. And over a long history, gods and buddhas overlapped in many forms.

Behind Zenpoji's dragon-god faith lie all of these: the Buddhist dragon-king faith, Japan's ancient reverence for water and the sea, and the prayers of people who live by the sea.

That said, this point matters, so let it be stated clearly. Within what could be confirmed for this article, there is no source that lets us assert the very process by which “Zenpoji's dragon-god faith came into being through a fusion of the Buddhist dragon-king faith and Japan's native water- and sea-deity beliefs.”

So this article treats Zenpoji's own founding history and the general historical background of Japan's dragon-king and water-deity faith as two separate things.

For fishermen, faith was about coming home alive

The word “faith” can feel a little difficult to some people.

But think of the prayers of fishermen and sailors, and the impression changes. For them, prayer was neither philosophy nor scholarship.

It was about coming home alive.

That the boat comes back safe again today. That a father comes home. That a husband comes home. That a son comes home. And that tomorrow, once more, they can put out to sea.

In an age when such “ordinary” things were anything but guaranteed, prayer to the beings who guard the sea, govern the water, and calm raging nature took deep root.

Zenpoji and fishing communities across Japan

Zenpoji is known as a temple for praying for safe voyages and bountiful catches — revered widely not only in Shonai but by fishing and shipping communities across Japan.

This is a very important feature when introducing Zenpoji.

That said, it does not mean “every fisherman in Japan worships at Zenpoji.” The accurate way to put it is that it “has been widely revered by fishing and shipping communities across Japan.”

And as for the specifics — which regions, from what era, and by what routes the faith spread — this article could not sufficiently cross-check them against primary or official sources within its scope.

So this article goes only as far as Zenpoji's widely known feature — that it “has drawn faith from fishing communities across Japan” — and makes no firm claims about the finer routes by which it spread.

The names of Zenpoji's dragon deities (as handed down at the temple)

At Zenpoji, two dragon deities are devoutly worshipped. According to tradition handed down at the temple, their names are Ryudo Dairyuo and Kaido Dairyunyo.

What's intriguing is that these two are said to be Sagara — one of the Eight Great Dragon Kings — and his third daughter, Zennyo Ryuo, who became disciples of the Buddha and received these names. In other words, the Buddhist dragon-king faith we've traced and Zenpoji's dragon deities are firmly connected within the temple's own tradition.

That said, these names and origins are things handed down as temple tradition and widely introduced in tourism and religious materials; the notation varies, too — “Ryugu Ryudo Dairyuo,” “Kaido Dairyunyo,” and so on. For publication, it is safest to confirm them against Zenpoji's official temple records and guides before committing them to print.

Kaibami Pond, famous for its “human-faced fish”

Some who know Zenpoji may be thinking, “Isn't that the human-faced-fish temple?”

Kaibami Pond (Kaibami-no-ike), near Zenpoji, became a huge topic in the 1990s for carp said to bear markings like a human face, and is known as one of the stages of Japan's nationwide “human-faced fish” boom.

But it would be a shame to let Zenpoji's appeal end at the “human-faced fish.” Zenpoji holds a far longer history of dragon-god faith and of the prayers of people who live by the sea.

In fact, Kaibami Pond is deeply tied to the dragon legend handed down at the temple. In that tradition, the dragon deities who appeared are said to have vanished into — or returned to — this pond, and it is spoken of as the dragons' sacred pond. That, however, is its place within the dragon legend, and is a separate matter from the human-faced fish (in fact a carp) that made news in the 1990s. It's best to avoid simply equating “the human-faced-fish pond” with “the dragon's pond.”

In the Meiji era, Japan separated “gods” from “buddhas”

For a long time, Japan sustained a culture of shinbutsu-shugo, in which Shinto and Buddhism were intermingled. But in the Meiji era, things changed dramatically.

The government pushed forward a policy of clearly separating gods from buddhas — the so-called shinbutsu bunri (the separation of Shinto and Buddhism).

Gods and buddhas that had been enshrined together were divided, and the relationship between shrines and temples was reorganized. It was an enormous turning point for Japan's religious culture.

Even so, changing the system doesn't easily erase a faith rooted in people. Faith is not built by systems alone; it grows over long years of daily life.

Looking at Zenpoji's dragon-god faith, you can clearly see that the mere category of “god or buddha” cannot fully capture Japanese faith.

That said, exactly what institutional changes Zenpoji itself underwent during the shinbutsu-bunri era is something this article does not assert in detail within its scope. Here, shinbutsu bunri is introduced as background to Japan's religious history as a whole.

If Dewa Sanzan is “the prayer of the mountains,” Zenpoji is “the prayer of the sea”

Speak of Tsuruoka and Dewa Sanzan — the three mountains of Haguro, Gassan, and Yudono — comes to mind. Enter the mountains, pray, and be reborn. Tsuruoka has long held a “faith of the mountains.”

But turn your gaze toward the Sea of Japan, and there is another prayer.

The prayer of the sea.

Those who live in the mountains. Those who live by the sea. Those who live by the rice fields. Each receives nature's blessings while also knowing its terror. And so people did not merely try to conquer nature — they felt gods and buddhas within it, and lived alongside it in prayer.

“Dewa Sanzan as the prayer of the mountains, Zenpoji as the prayer of the sea” is not an official historical classification. It is a contrast used within this article to make Tsuruoka's faith culture easier to grasp.

But set them side by side, and you can clearly see that Tsuruoka is a place that has nurtured prayer in both its mountains and its sea.

When you visit Zenpoji, look not only at the buildings but at the prayer

When you visit a temple, your eyes are naturally drawn to the grandeur of the buildings, the statues, the gardens, the photogenic scenery. That, of course, is one of the joys of travel.

But if you visit Zenpoji, pause for just a moment and consider.

How many people, here, have wished for the safety of family heading out to sea?

How many in the fishing community have prayed, “Let me come home safe once more”?

Think of that, and the dragon god ceases to be a thing of old tales alone.

It may be a form of prayer, born the moment human beings stood before a nature they could do nothing about.

So — why a dragon god, at a Buddhist temple?

Let's return to the first question.

“Why does a Buddhist temple honor a dragon god?”

The answer isn't a single line.

But if you've read this far, its shape is surely already visible to you.

The dragon tradition that Buddhism carried all this way. The reverence for water and the sea that has lived in this land since ancient times. And the long span of hours in which people who live by the sea pressed their palms together amid the daily risk of their lives. All of it came quietly together beside the sea in Tsuruoka — and that, I think, is the place called Zenpoji.

That it has drawn faith from fishing and shipping communities across Japan is surely because the dragon god has stood at the very center of that prayer, as a guardian of the sea.

It is not a story that reason alone can fully explain. But perhaps it is precisely because it can't be fully explained that people have pressed their palms together there.

God, or buddha — you don't have to settle on just one. People pray to the being that protects them. That accumulation is what has shaped Japan's culture of faith.

In Tsuruoka there is the “prayer of the mountains” of Dewa Sanzan, and the “prayer of the sea” of Zenpoji.

Pray to the mountains. Pray to the sea.

The history of people who have lived within nature remains, even now, in this land.

When you visit Zenpoji, don't look only at the dragon god — reach for the history of human prayer that lies behind it. It will surely make for a journey unlike simply seeing a temple.

A note on how information is handled in this article

This article describes the general religious history — the Buddhist dragon-king faith, the Naga, shinbutsu-shugo, and shinbutsu bunri — separately from Zenpoji's own origins and faith.

The names of the dragon deities, and the connection between Kaibami Pond and the dragon legend, are introduced as tradition handed down at the temple. On the other hand, the process by which the dragon-god faith came into being, the specific era and routes by which the faith spread to fishing communities across Japan, and Zenpoji's own transformations during the shinbutsu-bunri period are not asserted here, within what could be confirmed for this article.

For publication, it is appropriate to give priority to content confirmed through Zenpoji's official temple records, official website, and temple-issued materials, adding to or correcting the article as needed.