If you're gearing up for a trip to Japan and want to bask in the epitome of Japanese luxury and culture, make sure to include a visit to an onsen in your itinerary. Onsen, those natural hot springs scattered across the archipelago, offer not just a warm soak but a profound cultural experience. With over 25,000 hot springs gracing the land, Japan, nestled in the Pacific Ring of Fire, has turned onsen visits into a cherished tradition. Initially established as health retreats, onsens have evolved into a top-notch tourist draw, significantly shaping Japanese bathing practices. Families, couples, and friends often embark on weekend getaways solely for the purpose of unwinding in these hot springs, turning it into a ritual that fosters relaxation and social bonding.

Delving into the history of these hot springs, while their exact origins remain somewhat unclear, references to them date back to the Nihon Shoki, a text from the first century. Early onsen hotspots like Dogo-Onsen in Ehime Prefecture, Shirahama Onsen in Wakayama Prefecture, and Arima Onsen in Hyogo Prefecture are highlighted in historical texts like the Manyoshu. Onsen's popularity soared in tandem with the expansion of Japan's railway network, gradually becoming a pivotal player in the country's tourism scene. Initially deemed a luxury during the Kamakura period, onsen transitioned from exclusive health resorts for the elite to welcoming retreats for people from all walks of life. Today, they offer a serene escape from city life, especially during extended weekends and holidays.

Beyond their therapeutic warmth, Japanese onsens were historically considered to possess mystical and holy attributes due to the mineral-rich geothermal spring water. To be officially recognized by the Japanese government, an onsen must feature natural spring water with a temperature of at least 25°C and include specific mineral or chemical elements. Minerals like sulfur, iron, and magnesium, believed to have healing properties, contribute to the popularity of these natural hot baths. The Japanese onsen benefits extend beyond relaxation, tapping into the rich mineral content for potential health advantages. The charm of onsens extends beyond the hot springs themselves. Many onsen towns, known as onsen machi, have sprung up around these geothermal wonders, featuring traditional inns called ryokan. These establishments often utilize the natural hot spring water in their baths, complemented by the allure of local cuisine and regional specialties unique to each area.

For first-timers, stepping into an onsen can be a tad daunting, with its set of etiquettes. After stashing personal belongings in the locker room, the ritual begins with a thorough body wash. The actual bath experience offers various options, from water jets to outdoor spas and saunas. Using a wash towel to cover private areas while moving around is considered polite, and entering the bath sans clothing is the norm.

Navigating Japanese Hot Spring Etiquette

If you're wondering about attire, in general, you can't wear anything in the bathing area. However, it's wise to double-check, as some onsen—especially the unisex ones—may allow you to cover up. If you feel conscious, you can use an onsen towel to cover yourself before entering the water. It's also essential to walk carefully, as the minerals in the onsen can make the floor slippery. 

Typically, you'll find a locker room provided for storing your personal belongings and clothes. Here, you'll disrobe and stow all items in your locker, carrying only the locker key and a small wash towel with you to the spa. You have the option to bring your towel or purchase one at the front desk.

The initial step in any onsen experience involves a thorough body wash before immersing yourself in the water. An area with individual faucets is usually available, allowing you to sit and bathe using the provided body soap and shampoo. Your wash towel comes in handy for reaching those hard-to-access places. If there's no stool or wash bowl, you can typically find them stacked near the entrance; be sure to return them after use!

Once you're squeaky clean from head to toe, you can proceed to the bath. Depending on the onsen, various types of baths with different water temperatures may be available for your enjoyment. Many establishments feature water jets, outdoor spas, lukewarm baths, cold water baths, and saunas. Some onsens even provide neyu (寝湯), a shallow bathing area mildly warmed for relaxation, complete with a headrest for a moment of rest amid the warmth of the hot spring.

Here are some tips to enhance your onsen experience:

1. When moving around in the bathing area, it's polite to use your wash towel to cover your private areas.

2. Ensure that your wash towel, even if brand new, doesn't come into contact with the bath water when entering. If it does, wring it out outside the bath for hygiene reasons. When resting in the bath, it's proper to leave your towel on the side or even rest it on your head.

3. You might be asking yourself what Japanese onsen Clothes are, well… there isn’t any, meaning no bathing suits or underwear. While it might seem embarrassing from a Western perspective, the Japanese don't think twice about it—when in Rome, do as the Romans do!

4. Tattoos are generally prohibited, linked to their association with Japanese gangsters. While some ryokan may make exceptions, be aware that tattoos are often not allowed in public bathing areas. Kashikiri onsen (貸切温泉) offer a solution, as they can be privately rented, allowing individuals with tattoos to enjoy the benefits of onsen without restrictions.

Onsen Rules and Japanese Onsen Culture

Most onsens still require full nudity and prohibit tattoos, so thorough research is recommended before your visit. Remember to heed the signs in the changing rooms, shower before dipping into the onsen, and avoid letting your washcloth touch the onsen water. Embrace the experience and consider trying scenic outdoor onsens if available.

The Tattoo Conundrum:

Why are tattoos banned in onsens? The historical background in Japan associates tattoos, or Irezumi, with "something anti-social people get" or "something members of illegal organizations such as gangsters get." While some ryokan may make exceptions, tattoos are generally not allowed in public bathing areas. Private onsen, known as kashikiri onsen, can be an option for those with tattoos, providing a chance to enjoy the benefits of onsen without restrictions.

Mixed-Gender Onsen and Japan's Most Famous Hot Spring

Traditionally, men and women would bathe together in the same facility. However, these days, baths are usually segregated by gender, with mixed-gender onsen, or konyoku, becoming rare. Tokyo, for instance, has bans on such establishments.

As for Japan's most famous hot spring, Kusatsu Onsen in Gunma Prefecture takes the crown. Voted as the top onsen in the past two years by travel companies in Japan, it boasts the highest discharge amount in the country, with more than 32,300 liters per minute. The source of its hot water lies near Mount Kusatsu-Shirane, offering a truly remarkable onsen experience.

Whilst this onsen is not for humans it is also considered as a very popular Onsen to visit. Nestled in the snow-covered landscapes of Japan, particularly in areas like Nagano, you can find a one-of-a-kind onsen experience that involves more than just humans. These are the famous "Japanese monkey onsens," where Japanese macaques, also known as snow monkeys, take to the soothing hot springs much like their human counterparts.

In conclusion, whether you seek health benefits, stunning views, or simply a tranquil soak, Japan's onsens await, promising an experience that goes beyond the ordinary and delves into the rich cultural tapestry of the Land of the Rising Sun.