The ten Heavenly Stems
The Stems are Gap, Eul, Byeong, Jeong, Mu, Gi, Gyeong, Sin, Im, and Gye in Korean reading: 갑·을·병·정·무·기·경·신·임·계. They pair the Five Phases with yin or yang, creating two expressions of Wood, Fire, Earth, Metal, and Water.
A Stem is the visible upper character of each pillar. Readers often treat it as a clearer or more outward expression, while remembering that its meaning changes through every relationship around it.
The twelve Earthly Branches
The Branches are Ja, Chuk, In, Myo, Jin, Sa, O, Mi, Sin, Yu, Sul, and Hae: 자·축·인·묘·진·사·오·미·신·유·술·해. They correspond to years, months, days, and traditional two-hour periods and are also associated with the twelve zodiac animals.
Branches can contain hidden Stems, so they carry more than a single elemental label. This is one reason a real chart cannot be reduced to counting five colors.
Why the cycle has sixty combinations
Stems and Branches advance together in a repeating sexagenary cycle. Because there are ten Stems and twelve Branches, the compatible pairings return to the beginning after sixty steps.
In Saju, the pair assigned to each birth moment becomes one pillar. Calculating those pairs correctly requires calendrical rules, including solar terms and the traditional hour system.
Finding Stems and Branches in the Four Pillars
Look at one column at a time. The upper character is the Heavenly Stem and the lower character is the Earthly Branch. Repeat this for year, month, day, and hour before comparing the whole chart.
The day’s upper character is the Day Master. Its relationship to the remaining characters is part of the interpretation. A birth-year animal alone leaves out the other columns and the relationships that give a complete chart its context.
A simple way to study the chart vocabulary
Make two notes: one for the visible character and one for the explanation given by the reader. Keeping these separate helps you see when a statement describes the chart’s structure and when it offers an interpretation.
Move next to the Five Elements and yin-yang guides. They explain the shared vocabulary behind the names. You do not need to memorize every Korean name before asking how a specific relationship was interpreted.
Sources & further reading
Lucia’s guide is written in original language from the reference material below. Interpretive traditions vary by school and practitioner.