5 Fascinating Facts About Japanese Onsen Culture You Didn’t Know

Japan's hot spring culture, known as onsen (温泉), is more than just a relaxing soak—it’s a centuries-old tradition rooted in wellness and healing. From natural geothermal wonders to quirky customs, there’s so much to explore about these thermal baths. Here are five fascinating facts about Japanese onsen culture that might surprise you!

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1. Japan Has Over 27,000 Natural Hot Spring Sources

Thanks to its location on the Pacific Ring of Fire, Japan is home to over 27,000 natural hot spring sources and more than 3,000 onsen facilities! These geothermal springs are heated by volcanic activity, creating natural spas rich in minerals. Each region offers a unique bathing experience, from outdoor rotenburo (露天飲) with scenic mountain views to historic onsen towns that have been welcoming visitors for centuries.

2. You Can Boil Eggs in an Onsen (And They’re Delicious!)

One of the tastiest onsen traditions is onsen tamago (温泉卵), a soft-boiled egg cooked in the naturally warm waters. These eggs are gently simmered at low temperatures, creating a silky, custard-like texture similar to eggs benedict. If you visit an onsen town, you might spot steaming baskets of eggs being prepared—and trust us, they’re known to be a bit smelly from a distance but are delicious!

3. There Are Over 10 Types of Healing Onsen Waters

Japanese hot springs aren’t just for relaxation—they offer real health and skin benefits! There are 10 official types of onsen water, each with unique properties. For example:

• Sodium Bicarbonate Springs: Known for softening the skin and promoting smoothness.
• Sulfur Springs: Believed to relieve joint pain and improve circulation.
• Iron Springs: Known for alleviating anemia and fatigue.

These mineral-rich waters are revered for their therapeutic effects, making onsen bathing both a wellness ritual and a cultural experience.

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4. Tattoos? You Might Have Trouble Entering an Onsen

While tattoos are becoming more accepted worldwide, they remain taboo in Japanese onsen culture. Historically, tattoos were associated with organized crime (yakuza), and many traditional onsen still prohibit entry to people with visible body art. However, times are changing, and some onsen now allow tattooed guests or provide private baths for a more inclusive experience.

5. ♨️ The Official Onsen Symbol Explained

Ever wondered what ♨️ means? This iconic emoji represents onsen! The three wavy lines symbolize rising steam, while the curved line below represents a hot spring bath. You’ll find this symbol on road signs leading to onsen towns, making it easier to spot these serene retreats during your travels.

Experience Onsen Wellness for Pets with Shikohin x Shikohin Selection

At Shikohin x Shikohin Selection, we believe in bringing these healing traditions beyond Japan’s borders. Our upcoming Onsen Pet Wellness Minerals allow your furry friends to enjoy the same soothing benefits of hot spring minerals—crafted with care to nourish their skin and coat naturally.