Introducing Hidden Hot Spring Koyama Resort

Hello travelers! I’m Aikero, a writer for [SaruKuma].

Today I’m thrilled to introduce a hot spring tucked away in Matsubase Town, Uki City:
[Hidden Hot Spring Koyama Resort].Fellow SaruKuma writer Rikotama featured this onsen here before — and although it’s called a “hidden” hot spring, it’s actually so popular that many local fans already know and love it!

[Hidden Hot Spring Koyama Resort] A Mini Trip to a Tropical Resort — A Hot Spring So Relaxing You’ll Want to Soak All Day! (Matsubase Town, Uki City)

It’s one of my family’s all-time favorite onsen, so let’s dive in!
To reach Koyama Resort, turn off the main road and head up a winding hill. The road is narrow with sharp curves, so please drive slowly!

The good news? The parking lot is enormous — and there’s even a second lot, so you’ll never have to worry about finding a spot.“I’ve never been to Bali, but this has to be exactly what a Balinese resort feels like!”
That’s the first thought that hits you. The exotic atmosphere is simply gorgeous.

Photos can’t capture it, but the air is filled with the soft scent of incense! It’s a full sensory experience that instantly puts you in a holiday mood.There’s even a dog run on site! I wonder if the pups also catch a whiff of incense and think, “Hmm… something’s different here today!” (●＾o＾●)On the property you’ll find drink vending machines andeven an ice cream vending machine — perfect for cooling off after your bath! Near the front desk there’s also a fridge stocked with drinking yogurt.Even the restrooms smell wonderfully of incense.
Bath tickets are purchased at the ticket vending machine. If you’d like to use cashless payment, just speak to the staff at the front desk.

[Public Bath]
Adults: 690 yen
Children: 440 yen (up to elementary school age)

[Family Bath] ★No Reservations★
Weekdays 60 min 2,200 yen / Weekends & Holidays 50 min 2,500 yen
Weekdays 60 min 2,500 yen / Weekends & Holidays 50 min 3,000 yen
Open-air bath rooms: 50 min 3,500 yen (weekdays, weekends & holidays)
※Weekdays only: extend by 30 minutes for 600 yen

[Special Suite] ★Reservation & Prepayment Required by the Day Before★
3 hours: 10,000 yen for up to 4 people
Each additional hour: 3,000 yen
Each additional person: 1,500 yen (elementary school age and up)

There are two special suites: Barong and Garuda.
※Free karaoke is available in Barong only
※Outside food and drinks are welcome
※Please take your trash with you. Mini fridge included, no microwave
※Full-day private rentals are also available! Reserve at the front desk or by phone.

Towels and a face-wash set are also for sale, so you can come empty-handed!

The family baths are to the left as you exit the front desk. Just stepping out and seeing this view is already amazing!
Amandari, Amanusa, Amankila, Amanwana…
Quite a tongue twister, isn’t it?

I was always curious about the names, so I looked them up! They come from Sanskrit and mean “peaceful island,” “peace of mind,” “peaceful hill,” and “peaceful forest.” Such beautiful, fitting names!

One quick tip: the names are similar, so make sure you head into the right room!

Why You’ll Love Hidden Hot Spring Koyama Resort

And here we are — the moment you’ve been waiting for: the bath itself! The slightly dim lighting makes it incredibly relaxing.
The water sits around 40°C — comfortable enough that kids can hop in right away without complaining about the heat. Since it’s a semi-open-air bath, you can soak in the water or rest on the chairs and stay as long as you like.

And here’s the best part: Koyama Resort uses 100% natural, free-flowing hot spring water (gensen kakenagashi) — even the showers run with onsen water!
The front desk lent us some toys! They’re not all bath-specific, but kids are happy with any kind of toy, right?
And here’s the changing room.
The air conditioner runs but doesn’t have a remote control. It’s not freezing cold, so the circulating fan is a welcome touch.Whether you’re traveling with family or your special someone, Hidden Hot Spring Koyama Resort lets you experience that tropical resort feeling without ever leaving Kumamoto. Be sure to add it to your itinerary!

[Hidden Hot Spring Koyama Resort] A Mini Trip to a Tropical Resort — A Hot Spring So Relaxing You’ll Want to Soak All Day! (Matsubase Town, Uki City)

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Frequently Asked Questions

※Information is current as of the time of reporting. Prices and hours may change. Please confirm before visiting.