What Are the Hidden Stems? The Heavenly Stems Concealed Inside Each Earthly Branch (Residual, Middle, Principal Qi)

The hidden stems (支藏干, jijanggan) are the Heavenly Stems concealed inside a single Earthly Branch. Behind an outwardly visible earth character like Ja (子), Chuk (丑), or In (寅) there usually sit two or three stem energies arranged in order of season, revealing an inner grain and potential that the surface character alone can't show. Gwiraedang calculates these hidden stems deterministically, straight from the fixed table of standard Saju theory. They aren't a score that sorts good fortune from bad — they're a reference for self-reflection, a way to read the layered energies stacked inside one character.

Why are the hidden stems called "concealed stems"?

The Heavenly Stems are the energy of heaven that shows on the upper row of a Saju chart, and the Earthly Branches are the earth characters on the lower row — yet inside each branch, stem energies are also layered by season. Even though a branch looks like a single character on the surface, within it two or three stems are understood to take turns at work. That's why they're called jijanggan — the Heavenly Stems (干) hidden (藏) inside an Earthly Branch (支).

These hidden energies are usually divided into three seats — residual qi (餘氣), middle qi (中氣), and principal qi (正氣). Within a single month, weight shifts from the lingering energy of the previous season (residual qi), through the energy that mixes in the middle (middle qi), to the energy that represents the branch itself (principal qi). Influence grows in the order residual → middle → principal, and the heaviest of them, the principal qi, is also separately called the main qi (本氣). If you'd like the basics of the Heavenly Stems and Earthly Branches down first, reading the Heavenly Stems guide and the Earthly Branches guide first makes the hidden stems far easier to follow.

What are the hidden stems of the twelve Earthly Branches?

Here is the standard hidden-stem table that the Gwiraedang engine uses. The order in each line is residual · middle · principal, and the last stem (the principal qi) is that branch's main qi.

Ja (子): Im (壬) · Gye (癸) — main qi Gye (癸)
Chuk (丑): Gye (癸) · Sin (辛) · Gi (己) — main qi Gi (己)
In (寅): Mu (戊) · Byeong (丙) · Gap (甲) — main qi Gap (甲)
Myo (卯): Gap (甲) · Eul (乙) — main qi Eul (乙)
Jin (辰): Eul (乙) · Gye (癸) · Mu (戊) — main qi Mu (戊)
Sa (巳): Mu (戊) · Gyeong (庚) · Byeong (丙) — main qi Byeong (丙)
O (午): Byeong (丙) · Gi (己) · Jeong (丁) — main qi Jeong (丁)
Mi (未): Jeong (丁) · Eul (乙) · Gi (己) — main qi Gi (己)
Sin (申): Mu (戊) · Im (壬) · Gyeong (庚) — main qi Gyeong (庚)
Yu (酉): Gyeong (庚) · Sin (辛) — main qi Sin (辛)
Sul (戌): Sin (辛) · Jeong (丁) · Mu (戊) — main qi Mu (戊)
Hae (亥): Mu (戊) · Gap (甲) · Im (壬) — main qi Im (壬)

Some branches hold only two stems — like Ja, Myo, and Yu — while others, such as In, Sin, Sa, and Hae, split cleanly into three distinct energies. The earth characters Jin, Sul, Chuk, and Mi (the storage branches, 庫支) are seen as vaults that gather and keep even the energy of other seasons. Reading this grain alongside clues like the combinations and clashes of the branches or the symbolic stars makes it clearer why a given branch moves the way it does.

How are the hidden stems used in reading a Saju?

The hidden stems aren't just a table to memorize — they're the actual basis for calculating the Ten Gods (sipseong). Gwiraedang sets each branch's Ten Gods from its main qi (the principal qi), and at the same time assigns Ten Gods to each of the stems hidden inside the branch, by their relationship to the Day Master, marking them on the chart. So even branches with the same surface character can read differently depending on the hidden stems within them.

Another use of the hidden stems is rootedness (通根, tonggeun). When a Heavenly Stem on the upper row of the chart has the same Five Element sitting among the hidden stems of a branch below it, that stem is said to have sunk a root into the earth — to be "rooted." If the matching element sits in the principal qi (the main qi), the root is a deep, firm strong root (强根); if it sits only in the residual or middle qi, it's a shallow weak root (弱根); and if it's nowhere to be found, the stem is rootless and floating (虛). The Gwiraedang engine works this rootedness out deterministically too, reading the weight of a stem's strength differently depending on whether it has a root in the branches — even for one and the same stem. Whether the Day Master in particular is rooted is an important clue for gauging a strong or weak Day Master.

Reading the hidden stems this way lets you pick out energy that never surfaces among the Heavenly Stems yet lies latent inside a branch. For instance, if a Five Element that's missing from the stems of a chart is hidden in the hidden stems of some branch, you might take it that this energy works within you, or comes into play in a particular season of life. Still, the hidden stems are a supporting clue for reading a chart in three dimensions, so we never pin a person down from this one layer alone. How it all gets woven together is unpacked in how to read a Saju chart.

FAQ

How are the residual, middle, and principal qi of the hidden stems different? They're the order in which the energies act inside a single branch, and the difference in their weight. Residual qi (餘氣) is the energy carried over from the previous season; middle qi (中氣) is the energy that mixes in between; and principal qi (正氣) is the energy that represents the branch, carrying the greatest weight. Influence grows as you move from residual toward principal, and the principal qi is also called the main qi (本氣). When setting a branch's Five Element nature or its Ten Gods, this main qi is the reference point.

Are the hidden stems different from person to person? The makeup of the hidden stems for each branch is a fixed table in standard Saju theory, so it's the same for everyone. Ja (子) always has Im and Gye as its hidden stems, and that holds for anyone who draws their chart with a Ten-Thousand-Year (perpetual) calendar. What changes from person to person is which branches you have, and — since it depends on your Day Master — which Ten Gods those hidden stems are read as. If any terms trip you up, a Saju glossary is a good place to look them up. And remember that Saju itself isn't a tool that hands you a fixed destiny; it's a reference for understanding the temperament you were born with.

The hidden stems of a Saju aren't a fortune that declares good or bad luck — they're a reference for understanding the layered energies stacked inside each Earthly Branch, for self-reflection rather than fortune-telling.