The key to what makes Shiatsu different from most science-based, as well as complementary medical systems, is that it is soul medicine.   

The term ‘soul’ is western and can refer to different things in different theological systems; it is used to here to refer to the unchanging, original self.   For most of us, our souls are obscured by the busyness and drama of mind and body which are, by definition, in a state of ill-health.  The human condition is one in which we are identified with this noise of mind and body, but this is not who we really are.  Who we really are is the unchanging bit. 

In soul medicine, while we work with the stuff of mind and body because that is the material presented to us, we do not work for the primary benefit of mind and body.  This is because, working on mind and body is not where real help lies.  Real help, where change is fundamental, lies in addressing the soul to help steer its way back to consciousness and fulfilment.  This is why Masunaga called Shiatsu, the ‘King of medicine’; because it deals with health at the core.The crucial point about Shiatsu and the philosophy that underpins it is that the practitioner does not do the work for the client; this would actually be impossible.  You cannot cure the soul because there is no-thing to cure.  Instead, the practitioner brings consciousness to bear on the person’s mind/body distortions so that the soul can engage and do the work through conscious choice.  Only the true individual can actually choose to change.  You could cut off a patient’s arm to solve a problem and that is a kind of change; but unless the person involved is really authoring, or authorising this change at the level of conscious understanding and choice, then the original problem will simply re-emerge in some other way.
The job of the soul doctor is to call to the soul, buried at various depths under layers of mind and body.  As the original self comes to the fore so the distortions, or illnesses, become less relevant.  Health issues will often resolve in this process, but even when they do not, the individual’s relationship with them changes. 
When the soul is in charge then life has less drama.  This is what Buddhists mean by non-attachment.  When the soul is in the foreground, relationships improve because there is less mind-stuff and less unexpressed emotion (body) being brought into relationship and getting in the way of real contact.  When relationships go better, life is more fulfilling. Fulfilment is health.
To practice soul medicine takes one thing: commitment to the truth of how it is, performed in relation to others.  Practicing Shiatsu with this commitment is the thread that can hold apparently different styles together.  Different styles of working with touch reflect the different characters of the practitioners engaged in this process.  To that extent, what we do is different.  But the guiding philosophy is clear; the intention to know Truth.  As a group, were we to focus on this philosophical base, rather than on differences in techniques and styles, I suggest we would find greater confluence and community.
As soon as the work becomes focused on the mind/body distortion as something interesting in itself and something to change, then it stops being soul medicine.  It starts to become about techniques and it narrows down.  The distortion is interesting to the soul doctor only as a gateway to the original self. 
Although we find in soul medicine that there is nothing to do, this is not doing nothing.  It is the hardest discipline; of putting one’s own mind and emotion body aside time and again and again and again in relation to the other.  A treatment is giving the other your attention through the medium of touch and being with them and setting aside your own mind/body.  By doing this you also clarify your own mind/body distortion.
There is nothing otherworldly or mysterious about it.  The mystery is our lostness.  Soul medicine is about coming home.  It is awakening to the full, mundane beauty and enoughness of the now of how it is.
Yet knowing this is one thing and practicing it is another.  How do we learn to do this?  There is no easy answer.  However, we do know it is possible to perform soul medicine and also that it is possible to learn it.  But both things are different for each person and learning has to be something undertaken as a personal service and surrender to Truth.  It takes time and repetition and it usually helps to have a teacher who has been there before; at some point we all need help to face down the monster of our own minds and emotions or we will be beguiled by their whispers. 
A teacher is not someone who necessarily teaches you, though it may help if they understand teaching and learning and have something to convey.  A teacher is someone you choose to learn from and ideally someone who is committed to helping you and knows what help looks like.  Once those things are in place, then it is about discipline and hard graft.  And it is worth all of it, even for one brief glimpse of the diamond that is the soul shining through.

Alice Whieldon is the co-author of Sei-ki: Life in Resonance, the secret art of Shiatsu 2011, Kishi & Whieldon, Singing Dragon.  Also author of: Mind Clearing: the key to mindfulness mastery 2016, Singing Dragon.  She is a Senior Fellow of the Higher Education Academy and currently Chair of the Shiatsu Society (UK).  She has Seiki and Mind Clearing practices in London and Norwich and leads regular workshops in both.  Her next UK workshop will take place in London, April 22/23 2017 at the BSS venue.  See for details.