Maybe you noticed things as a child that others didn't seem to notice, the mood in a room or tension between people who hadn't said a word. And maybe you were told that you were too sensitive or imagining things. Many people eventually stop talking about it, but they don't stop perceiving it.
Today there's a name for this, high sensitivity, or HSP (Highly Sensitive Person). The psychologist Elaine Aron estimates that about 15 to 20 percent of people have a nervous system that processes stimuli more intensely than average. That applies to sounds, light and the emotions of others, and many highly sensitive people report subtler perceptions as well, which are hard to put into words.

Fragile or receptive? 感受
High sensitivity is often treated as something to be managed. The usual advice is to set boundaries, shield yourself and feel less. That can be helpful in everyday life, but it's only one side.
In the spiritual traditions of Japan, the ability to perceive subtle energies has a different value. It's seen as an ability that can be refined through practice. For energy work, I'd even say it's a very good starting point. The point isn't to dampen your sensitivity, but to understand it and learn to handle it.
Hibiki and byōsen 病腺
In Reiki there are two terms that highly sensitive people tend to understand right away, hibiki 響き and byōsen 病腺. Hibiki is the feeling in your hand that rings and vibrates like a bell, such as tingling, pulsing, warmth, coolness or a slight pull. Byōsen, going by the characters, means sensing illness in the body, mind or soul, the ability to notice ahead of time where something is out of balance. Put simply, byōsen is recognizing where something isn't right, and hibiki is what your hand feels there.
For many people, this kind of perception takes some practice. For highly sensitive people it's often there from the start, because both rely on the same ability, registering fine differences below the threshold of ordinary attention. You can read more about this in the article on hibiki and byōsen.

Protection and stability 護身
In my experience, the bigger challenge for highly sensitive people isn't the perception itself, but what comes afterward. Some people feel the moods of others as if they were their own, get flooded by stimuli in crowds, or need hours to come back to themselves after an intense conversation.
In esoteric Buddhism and Shugendō there's a protective practice for this, goshinbō 護身法, literally "method of protecting the body." In Shingon it's one of the first things a practitioner does before any ritual. In my Kuji Kiri 1, the goshinbō is one of the foundation practices. It isn't about building a wall around yourself, but about holding your own energetic space, open to what nourishes you and stable against what drains you. More on this is in the articles on negative influences and protection of the soul.
Kannō, resonance 感応
In Buddhism there's a term that describes very well what many highly sensitive people experience, kannō 感応. Kan 感 means to feel or to be moved, and ō 応 means to respond. In Buddhist thought it describes the meeting between the practitioner, who reaches out with sincere feeling, and the Buddha, who responds. There's even a set phrase for it, kannō dōkō 感応道交, "feeling and response meet on the path."
For a highly sensitive person, that means that what you perceive has a place, a name and a long tradition behind it. You're not "too much." You're receptive, and in the language of the old traditions, receptivity is a precondition for spiritual practice.

High sensitivity isn't a prerequisite for Reiki, of course, and Reiki doesn't replace psychological support if you need it. Many highly sensitive people, however, find in Reiki a way to understand their perception better. Do you recognize yourself in this description?
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Shingon Reiki offers highly sensitive people a space where their perception is finally understood. Discover which entry suits you.
Your path in Shingon Reiki Meet Mark & Eileen