Japanese astrology comparison: zodiac versus Sukuyo
Japanese astrology includes multiple systems: the animal-year cycle, 12 zodiac signs, and Sukuyo’s 27 birth mansions use different inputs and outputs.
Overview
Clarify whether the reader wants an animal year, a zodiac sign or a birth mansion before choosing a tool.
At a glance
- Animal-year cycle
- 12 animals
- Zodiac signs
- 12 signs
- Sukuyo product roster
- 27 mansions
Clarify the intended meaning
Someone asking for a Japanese zodiac sign may mean an animal year rather than a Sukuyo mansion.
Ask which output they want before recommending a calculator.
Year labels are not mansion labels
A year-based animal designation does not directly identify the lunar month/day used by Sukuyo.
People sharing an animal year can have different birth mansions.
Twelve palaces are another layer
T1299 also contains twelve-palace terminology, but that does not make the 27-mansion lookup a twelve-animal system.
The palace/four-foot reference has its own structure and precision boundary.
Use the correct tool
For a Sukuyo mansion, use the date-based Sukuyo calculator. For another zodiac system, retain its own input requirements and settings.
Do not rename a returned mansion as a Sun sign simply to match a search phrase.
Keep interpretations separate
Different traditions can be explored as cultural frameworks without pretending their labels are equivalent.
Neither a shared animal nor a shared mansion proves that two people have the same personality.
Check one person without collapsing labels
Record the birth year for an animal-cycle result and the complete birth date for a Sukuyo lookup in separate rows. Keep a twelve-sign result separate again with its own body and zodiac settings.
One person can legitimately receive three different labels because the systems calculate different quantities; no combined label is implied.
Sources and editorial basis
- 宿曜經 · T1299 卷上卷上「分定宿直品第一」: twelve-palace/four-foot structure differs from twelve-branch nomenclature.Historical text for mansion names and calendar tables. Its table is not identical to OpenFate’s modern 27-mansion lookup; it does not establish predictive validity.
- OpenFate Sukuyo calculator and calculation conventionEditorial code check 2026-09-10, policy 1.0.0: japanese-zodiac; policy.ts, constants.ts, engine.ts and traditional-cycles.ts. Product settings are not an independent historical authority; practical examples are OpenFate editorial applications.Product-specific input and output reference. Editorial checks also inspected policy 1.0.0 and the month-start constants on 2026-09-10; those implementation checks are not an independent traditional authority.
- 国立天文台 暦Wiki：十二支暦Wiki「十二支」: twelve names and their readings; not a birth-mansion calculation.Reference for the twelve-branch nomenclature, distinct from a 27-mansion birth-date lookup.