For me, grounding is the foundation of every energetic practice. Before energy can rise to the heart and the mind, it needs roots, an anchor in the body that holds. In Reiki a lot is said about chakras, light and cosmic connection, and that has its place. Without grounding, though, it's easy to lose your footing.
In Japanese culture this is almost self-evident. Every martial art begins with the stance, every tea ceremony with sitting, and every calligraphy with the breath in the belly. In Shingon, earth (chi 地) is the first of the five great elements (godai), which are also represented in the five-tiered stone pagoda gorintō 五輪塔. Its seed syllable is the Siddham A, which in Shingon stands for the "originally unborn," the origin of everything.

Why grounding comes first 地 · Chi
Think of a tree. Its crown reaches into the sky and its leaves catch the light, but what holds it is something you don't see, the roots. The deeper they go, the higher the tree can grow. I find this comparison fits the human energy body quite well.
Many people who come to energy work perceive a lot, sometimes too much. If you're highly sensitive, you may know sensory overload or the feeling of not being fully in your body. Then the temptation is strong to orient yourself upward, toward the subtle and away from what feels heavy. In my experience that tends to make it worse. If you aren't grounded, it's hard to hold energy, and it runs through you a bit like water through a sieve. That's why grounding has such an important place in Shingon Reiki practice. The body becomes a vessel and the feet become roots.
The four-stage grounding 四段
In Shingon Reiki we work with a grounding in four stages, which guides the flow of ki from the center of the body down into contact with the earth. Here's a short overview of the four zones:
The hara. The tanden 丹田, a little below the navel, is the starting point. This is where ki gathers, in what in Japanese is called hara 腹, the body's center of gravity.
The knees. The knees are the hinge between the upper and lower body. In martial arts, the position of the knees decides between stability and mobility.

The ankles. The ankles connect a firm stance with movement, because they adapt to every unevenness of the ground. They stand for the ability to stay grounded without becoming rigid.
The soles of the feet. The soles are where body and earth meet. In martial arts such as Ninjutsu or Bagua, contact with the ground is the basis of every technique, because if you don't feel the ground, you can't react.
How the hands are placed and how the flow is guided from stage to stage is something we practice together. Many people describe warmth, tingling or a pleasant heaviness in the legs, and some feel as if something that has been held for a long time can finally drain away downward.
Grounding in everyday life 日常
Grounding isn't limited to Reiki practice. It starts the moment you stand consciously, for example barefoot on grass, on stone or on earth. I walked the Shikoku pilgrimage to all 88 temples on foot, through mountains and valleys, and on a path like that you inevitably get to know your feet very well. Simple things like standing calmly for a couple of minutes, walking barefoot on natural ground, or letting your breath sink down into your belly can make a noticeable difference.
In the martial arts, grounding isn't a relaxation technique at all. In Ninjutsu and Budō, your stance decides whether you keep your balance or get thrown. A calligrapher who isn't grounded will have a trembling brush, and a meditator who isn't grounded tends to meditate in the head instead of the body. The grounding in Shingon Reiki stands in this tradition, as an anchoring in your own body and therefore in your own strength.

The earth element 地 isn't only physical. It also stands for reliability and substance, for what remains when everything else is moving. Where in your body do you feel most grounded right now?
Discover the grounding practice
The four-stage grounding is part of Shingon Reiki practice. If you like, have a look at which entry fits you.
Your path into Shingon Reiki Chakras and Reiki