Last Updated on October 10, 2026
Inada is a well-known Japanese massage chair manufacturer with a long history of developing robotic massage technology. The company has built a reputation for its attention to comfort, stretching programs, and traditional Japanese massage techniques. If you’re looking for a massage chair that focuses on flexibility and relaxation, the Inada Flex 3S is an interesting model to consider.
The Inada Flex 3S massage chair was designed to combine Shiatsu-style massage with mechanical stretching movements. Unlike some massage chairs that mainly focus on strong rollers, this model places considerable emphasis on shoulder stretching, body positioning, and full-body relaxation.
However, the Flex 3S is an older model. As of 2026, it is not widely available as a new product in some markets, and buyers may need to look for remaining dealer stock or a used unit. In this Inada Flex 3S massage chair review, we’ll examine its features, specifications, advantages, disadvantages, and whether it is still worth buying.
Inada HCP-S373 Flex 3S Massage Chair Review
The Inada HCP-S373 Flex 3S is a Japanese-made massage chair designed for home use. It combines mechanical rollers, air compression, and stretching movements to provide a relaxing full-body massage experience.
The chair was developed around Inada’s approach to Shiatsu-style massage and assisted stretching. Its programs focus on different areas of the body, including the neck, shoulders, back, arms, and legs.
One of its most interesting features is the stretching system. During selected programs, airbags and mechanical movements work together to position different parts of the body and provide gentle stretching sensations.
The Flex 3S also includes automatic Shiatsu-point location in selected massage sessions, adjustable air pressure, reclining controls, and several manual massage options.
Although newer chairs may offer touchscreens, mobile apps, and additional automation, the Flex 3S remains an interesting example of Inada’s traditional Japanese massage chair engineering.
Technical Specifications of Inada Flex 3S
The specifications below are based primarily on the North American HCP-S373A operating manual. The original article identifies an HCP-S373(B) variant, so confirm the exact model plate before relying on electrical specifications or regional features.
| Feature | Inada Flex 3S |
|---|---|
| Model Family | HCP-S373 |
| Verified Manual Variant | HCP-S373A |
| Manufacturing | Made in Japan |
| Massage System | Mechanical rollers and air compression |
| Automatic Programs | 6 main preset sessions |
| Manual and Focused Operations | 16 listed operations |
| Massage Techniques | Kneading, tapping, rolling, Shiatsu-style movements, and stretching |
| Roller Travel | Approximately 27.6 inches |
| Roller Width | 3 adjustment levels |
| Kneading Speed | 3 levels |
| Tapping Speed | 3 levels |
| Air Massage | Arms, seat, and legs |
| Air Pressure | Adjustable low, medium, and high levels |
| Reclining Angle | Approximately 115–165 degrees |
| Chair Weight | Approximately 165 lb |
| Chair Width | Approximately 33 inches |
| Power | AC 120V, 60Hz for HCP-S373A |
| Power Consumption | 150W for HCP-S373A |
| Outer Upholstery | Synthetic leather |
| Availability in 2026 | Older model; limited dealer stock or used market |
| Warranty | Depends on region, seller, and purchase condition |
Important: Different regional versions may use different voltage requirements. Never connect the chair to a power supply that does not match its rating label.
Main Features of the Inada Flex 3S Massage Chair
The Flex 3S includes several functions designed to make massage sessions more comfortable and customizable.
- Full-body massage and stretching programs.
- Focused shoulder massage.
- Automatic Shiatsu-point location in selected sessions.
- Mechanical roller massage for the back.
- Air compression massage for the arms, seat, and legs.
- Adjustable air pressure.
- Multiple kneading and tapping speeds.
- Manual roller positioning.
- Automatic reclining mechanism.
- Stretching movements for different body areas.
- Dedicated remote control.
- Emergency stop function.
- Adjustable leg rest.
- Removable or adjustable cushioning components.
These features were impressive for their time. However, it’s important to judge the chair based on its actual condition and functionality rather than assuming that it performs like a newly released premium massage chair.
Features of Inada HCP-S373 Flex 3S
Advanced Stretching Techniques
One of the main attractions of the Inada Flex 3S is its stretching system.
The chair offers a Massage & Stretch program that combines roller massage with lighter stretching movements. It also includes a Full Body Stretch session designed for people who prefer a more noticeable stretching sensation.
The mechanical reclining system, airbags, and massage rollers work together during these programs.
This can provide a relaxing stretching experience, especially after sitting for long periods or dealing with everyday muscle tightness.
However, the stretching intensity may not suit everyone. Start with a comfortable setting and stop immediately if you experience pain or unusual discomfort.
The Flex 3S is designed for relaxation and muscle comfort, not for treating spinal disorders or replacing physical therapy.
Hot Stone-Style Massage
Some Flex 3S configurations have been advertised with a warming function for the hands and feet, designed to create a relaxing hot stone-like sensation.
Heat can make a massage feel more comfortable, particularly for people who enjoy warmth around their hands or feet.
However, don’t confuse this feature with actual hot stone therapy. The chair does not use heated massage stones.
Heating features should also be verified on the exact model, because regional versions and seller descriptions may differ.
If you have reduced heat sensitivity or a medical condition affecting circulation, consult a healthcare professional before using heated massage features.
Shiatsu-Point Locator
The Flex 3S includes an automatic Shiatsu-point locator in selected massage sessions.
Before certain programs begin, the chair uses its mechanism to determine appropriate massage positions based on the user’s body.
This helps the rollers target different areas of the back and shoulders more comfortably.
However, the system doesn’t medically identify pressure points or diagnose muscle problems. It is a positioning feature intended to improve the massage experience.
If the rollers feel uncomfortable, adjust your seating position or massage intensity.
Posture-Focused Stretching
Another notable feature is the chair’s posture-focused stretching program.
During selected sessions, the airbags help position the shoulders and body while the mechanical system performs stretching movements.
This can be particularly enjoyable for people who spend many hours sitting at a desk.
However, the chair cannot guarantee permanent correction of rounded shoulders, poor posture, or spinal alignment.
Long-term posture improvements generally involve regular movement, appropriate exercise, workstation adjustments, and professional guidance when necessary.
Think of this feature as an assisted stretching option rather than a treatment for structural posture problems.
Mechanical Roller Technology
The Flex 3S uses a mechanical roller system that moves along the back to perform kneading, tapping, rolling, and Shiatsu-style massage movements.
The operating manual lists adjustable roller width and massage speeds, allowing users to customize the experience.
Some older product descriptions refer to this as a 3D massage system. However, the term should not be confused with the electronically adjustable 3D or 4D rollers found in many newer massage chairs.
The Flex 3S offers mechanical massage adjustment, but its precise functions should be judged according to the controls and specifications of the particular unit.
If you’re comparing older and newer massage chairs, this distinction is important.
Full-Body Air Compression
The chair includes air massage functions for the arms, seat, and legs.
During a massage, airbags inflate and release pressure around selected body areas.
The user can adjust air intensity between low, medium, and high settings.
Air compression adds another sensation to the mechanical roller massage and may help users feel more relaxed.
However, it isn’t suitable for everyone. People with certain circulation problems, blood clots, or other medical conditions should seek medical advice before using compression features.
Reclining and Leg Rest Adjustment
The Inada Flex 3S has an automatic reclining backrest and an adjustable leg rest.
The North American operating manual specifies a reclining range of approximately 115 to 165 degrees.
Users can adjust the chair’s position through the remote control to find a comfortable posture.
Because this is a fairly large chair, you should also consider the space needed behind it when reclining.
Before buying a used unit, test the reclining motor and leg rest carefully. Both should operate smoothly without unusual grinding or repeated error messages.
Massage Programs and Remote Control
The Flex 3S includes six main preset sessions in the HCP-S373A manual.
Four are described as healthcare sessions, while two are conditioning sessions. The chair also provides focused and manual massage operations.
The remote control lets you select the massage type, adjust intensity, position the rollers, and control reclining functions.
Although the remote looks more traditional than the touchscreens found on modern chairs, its dedicated buttons can make frequent adjustments straightforward.
If you’re buying secondhand, make sure the remote is included and every important button works.
Advantages of the Inada Flex 3S Massage Chair
- Japanese-made construction.
- Dedicated stretching and massage programs.
- Comfortable shoulder-focused massage functions.
- Shiatsu-style roller movements.
- Air compression for several body areas.
- Adjustable massage speed and intensity.
- Automatic reclining and leg rest adjustment.
- Multiple manual massage options.
- Traditional remote control with dedicated buttons.
- Useful combination of stretching and relaxation features.
Disadvantages of the Inada Flex 3S Massage Chair
- An older model with limited availability in 2026.
- Replacement parts and servicing may be difficult to arrange.
- Lacks some features found on newer premium massage chairs.
- Large and heavy, making transportation difficult.
- May require additional clearance when reclining.
- Upholstery and airbags may show wear on used units.
- Warranty availability varies by seller and region.
- Not a medical treatment for posture disorders or chronic pain.
Is the Inada Flex 3S Still Worth Buying in 2026?
The Inada Flex 3S can still be worth considering if you particularly enjoy traditional Japanese massage techniques and stretching programs.
Its mechanical massage system, airbags, and body-positioning features provide a different experience from basic massage chairs.
However, availability is a major concern.
A current Inada distributor listing shows the Flex 3S as sold out, and the model is absent from some current regional product collections.
This means you may need to search for remaining dealer inventory or purchase a used chair.
If you’re considering a used Flex 3S, inspect it carefully. Replacement parts and specialized repairs can become expensive, particularly for older robotic massage chairs.
Before paying, test every automatic program, airbag section, roller movement, reclining function, and remote-control button.
Also, compare the total purchase and repair cost with the price of a newer chair that includes a current manufacturer’s warranty.
What to Check Before Buying a Used Inada Flex 3S
Because the chair is an older model, its condition matters just as much as its original specifications.
- Model number: Confirm whether you’re buying HCP-S373A, HCP-S373B, or another regional version.
- Electrical rating: Check the voltage and frequency on the rating label.
- Roller movement: Make sure the rollers move smoothly without stopping unexpectedly.
- Airbags: Test the arm, seat, and leg compression functions.
- Stretching programs: Confirm that the recline and stretching movements operate normally.
- Remote: Check every button, especially emergency stop and reclining controls.
- Upholstery: Look for tears, peeling, excessive wear, or damaged cushioning.
- Service support: Ask whether replacement parts and qualified repair technicians are still available.
Don’t buy a used massage chair based only on the seller’s statement that it turns on. A chair can power up while still having faulty airbags, motors, or roller components.
Who Should Use the Inada Flex 3S?
The Flex 3S may suit people who enjoy full-body massage, shoulder-focused programs, and assisted stretching.
It may be especially appealing if you prefer a traditional Japanese massage style rather than a chair centered on entertainment features.
However, it isn’t suitable for everyone.
People who are pregnant, have a history of blood clots, significant cardiovascular problems, recent injuries, osteoporosis, or other conditions that may make massage unsafe should consult their healthcare professional before use.
People with impaired sensation should also be cautious with compression and heating functions.
Height and weight limits must be checked against the exact model’s operating manual. Avoid relying solely on the original article’s 240-pound and 6-foot-2-inch claims without confirming them for your chair.
Most importantly, a massage chair should never be used as a substitute for medical evaluation when pain is persistent, severe, or accompanied by numbness or weakness.
Inada Flex 3S vs. Modern Massage Chairs
The Flex 3S was designed around mechanical massage and assisted stretching.
Modern massage chairs may offer additional features such as advanced body scanning, adjustable 4D rollers, Bluetooth speakers, smartphone controls, and more automated massage options.
For example, Inada’s current regional collections include models such as D.Core 2, Therapina Robo, and i-FiT Pro.
These models should not be treated as direct replacements for the Flex 3S, because their features, prices, and availability differ.
However, they are useful examples of how Inada’s product lineup has evolved.
If you’re comparing a used Flex 3S with a newer chair, focus on massage comfort, available features, service support, warranty, and total cost rather than the number of programs alone.
Inada Flex 3S Warranty and Replacement Parts
The original Flex 3S was sold with warranty arrangements that varied by market and distributor.
Some older U.S. listings mentioned three-year limited warranty coverage, while current Inada distributors in other regions offer different terms.
Therefore, buyers should not assume that a three-year warranty applies to a newly purchased or used Flex 3S in 2026.
The operating manual also explains that after-sales service is handled through the relevant Inada distributor.
For used chairs, ask whether the seller can provide the original receipt, serial number, maintenance history, and details about available replacement parts.
Be particularly careful with units imported from another country because electrical compatibility and repair support can differ.
Final Thoughts: Is the Inada Flex 3S a Good Massage Chair?
The Inada Flex 3S remains an interesting massage chair because of its focus on stretching, Shiatsu-style movements, and traditional Japanese massage techniques.
Its shoulder-focused massage, air compression, adjustable rollers, and reclining system provide a range of relaxation options.
However, the chair is no longer a recent model. In 2026, its condition, availability, and repair support are more important than the awards or customer reviews it received when first released.
If you find a well-maintained unit at a reasonable price, it may still provide a comfortable massage experience.
But if the chair requires expensive repairs or lacks a reliable service provider, buying a newer massage chair may be the better decision.
Overall, the Inada Flex 3S is worth considering for people who specifically value assisted stretching and Japanese-style massage. Just make sure the chair works properly and that you understand the limitations of purchasing an older model.
Frequently Asked Questions
1. Is the Inada Flex 3S still available in 2026?
The Flex 3S is an older model and is sold out through at least one distributor. Availability may be limited to remaining stock or used units.
2. How many automatic massage programs does the Inada Flex 3S have?
The HCP-S373A operating manual lists six main automatic preset sessions, along with focused and manual massage operations.
3. Can the Inada Flex 3S correct poor posture?
Its stretching programs may help users feel more relaxed, but there is no reliable evidence that the chair permanently corrects posture problems.
4. How much does the Inada Flex 3S weigh?
The HCP-S373A operating manual lists a weight of approximately 165 pounds. Other regional variants should be checked individually.
5. Does the Inada Flex 3S come with a warranty?
Warranty coverage depends on the country, distributor, and purchase condition. Used chairs may have no transferable warranty.
6. Is it safe to buy a used Inada Flex 3S massage chair?
It may be a reasonable purchase if the chair is working properly and qualified repair support is available. Test the rollers, airbags, remote control, reclining system, and safety functions before buying.