Sanso Spa onsen at Raiden Resort

Mind & Body Retreat

Wellness and Onsen

Opening in the Summer 2026

Surrounded by ocean and mountains, Raiden Resort remains one of Hokkaido's quiet hidden places. In a fast-moving world, time to pause becomes essential. Rediscover the beauty of returning to your breath, reconnect with nature, and restore balance through calm, attentive care of body and mind in our traditional and modern wellness programs and natural onsen experiences.

Five Oxygen-Inspired Dimensions

Where It's Just You and Nature

Moving beyond the conventional "Five Senses," Sanso Spa expresses its identity through five oxygen-inspired dimensions, each connected to an emotion, a treatment theme, and a natural element.

Ki

Air: Breath and Oxygen

Each session starts with a gentle breathing exercise to calm the mind and prepare the body for deep relaxation.

Ryu

Flow: Circulation and Energy

Each of our treatments is designed not only to relieve tension through touch but also to enhance the natural circulation of oxygen, blood, and fluids within you.

Chi

Ground: Warmth and Presence

Each of our treatments begins with soothing warmth applied to the body, easing tension and guiding you into a state of ultimate relaxation.

Hikari

Light: Clarity and Glow

Each session concludes with a gentle, soothing facial massage, leaving both your skin and mind clear, refreshed, and radiant.

Sei

Stillness: Rest and Harmony

Enjoy our soothing spa music and our Japanese-inspired massage oils: Calm, Release, Balance, Breathe, and Charge.

Wellness Offerings

Treatments & Rituals Highlights

清流 SeiRyu

Signature Water Treatment

Raiden's signature water treatment inspired by the purity and rhythm of mountain streams. Lie beneath five to seven Vichy showerheads as warm water cascades over the body, combined with body exfoliation or wraps for deep restoration.

和鍼 Washin

Japanese Acupuncture

Experience Japanese acupuncture, 'Washin.' Using needles developed in Japan that are much thinner than traditional Chinese acupuncture needles, the treatment feels especially gentle and comfortable.

海 Umi Ritual

Sea Day Program

A one-day ritual program combining Yoga, Zen meditation, and massages inspired by the surrounding ocean landscape. Reconnect with yourself through nature, movement, and stillness.

山 Yama Ritual

Mountain Day Program

A one-day ritual program combining Yoga, Zen meditation, and massages inspired by the surrounding mountain landscape. Reconnect with yourself through nature, movement, and stillness.

Natural Hot Springs

Onsen

Iwanai has a long history of natural hot springs. Within just one kilometer of the resort, two distinct types emerge — the seawater-derived Atatamari-no-Yu ("warming spring") and the mountain-derived Bihada-no-Yu ("beauty spring"). Both are naturally rich in minerals and flow at high temperatures, allowing guests to enjoy pure, free-flowing onsen water without additional heating. At Raiden Resort, guests experience Atatamari-no-Yu, a chloride-rich seawater hot spring known for its warming and restorative effects. The mineral-rich water helps retain body heat, support circulation, ease muscle fatigue, and promote relaxation after skiing, outdoor activities, or travel.

Public Baths

Public baths for men and women are available to all guests without reservation, including indoor bath, outdoor bath, and hinoki sauna.

Private Onsen

A private onsen for those seeking a more secluded experience. Perfect for couples or families wanting a private bathing experience.

Onsen Hours: 06:00 AM – 11:00 PM

Plan Your Visit

Begin Your Journey

Spa treatments and private onsen suites are available by reservation. Public baths are complimentary for all resort guests. Contact our concierge to curate a personalised wellness programme during your stay.