Nine Star Ki Directions (九星氣學方位)

Kigaku 方位取り — Which Way the Year Wants You to Go

Overview

Nine Star Ki (九星気学, Kyusei Kigaku) is one of Japan's most popular systems of divination, and its most practical use is directional: choosing auspicious directions to travel, move house or begin something important, and avoiding the afflicted ones. This is 方位取り (hōi-tori, 'taking a direction'). Where the natal side of Nine Star Ki gives you your birth star, the directional side asks a different question — for this particular year, which of the eight compass directions are open and which are closed? This endpoint builds the year's chart and marks the directions to avoid, including the ones specific to your own birth star.

Origin & history

Nine Star Ki descends from the same ancient Chinese cosmology as Feng Shui and the Luoshu (Lo Shu) magic square — the 3×3 grid in which the numbers 1–9 are arranged so every row, column and diagonal sums to 15. Each of the nine numbers is a 'star' with an element and a compass direction. The system was refined in Japan in the early twentieth century (notably by Shinjiro Sonoda and Yoshifusa Matsuda) into the Kigaku practised today. Its directional method rotates the Luoshu each year so that the year's ruling star sits in the centre, and reads the resulting arrangement to find the year's favourable and unfavourable directions.

The directional afflictions are the heart of the practice. The 五黄殺 (Goō-satsu) is the direction where the powerful, destructive 5-Yellow star has landed for the year; the 暗剣殺 (Anken-satsu, 'hidden sword') is the direction directly opposite it. The 歳破 (Saiha, 'year-breaker') is the direction opposing the year's zodiac animal. These three are the same for everyone. Two more are personal: the 本命殺 (Honmei-satsu), the direction where your own birth star has landed this year, and the 本命的殺 (Honmeiteki-satsu) opposite it. Traditionally these directions are avoided for significant moves; the remaining directions, especially those whose star nourishes your own by the five-element cycle, are candidates for auspicious travel. Because the year turns at 立春 (around 4 February), a January date still belongs to the previous year's chart — a subtlety this engine handles by computing the exact solar term.

How it works

Give a date (and optionally a birthdate). The engine determines which Nine-Star year the date falls in — the year turns at 立春, computed precisely from the Sun's longitude reaching 315° — and finds the year's ruling star. It rotates the base Luoshu square so that star sits in the centre, producing the arrangement of all nine stars across the eight directions. It then flags the afflicted directions: 五黄殺 (where the 5-Yellow sits), 暗剣殺 (opposite), and 歳破 (opposite the year's zodiac-branch direction). If you supply a birthdate, it also computes your birth star (with the same 立春 rule) and flags your personal 本命殺 and 本命的殺. Finally it notes, for each direction, the five-element relationship between that direction's star and your birth star, so the year-level favourable directions stand out. Everything is exact arithmetic on the fixed Luoshu.

Good for

Use cases

The Year's Chart

Send a date and get the full annual Luoshu arrangement — which star sits in each of the eight directions this Nine-Star year.

Directions to Avoid

See the 五黄殺, 暗剣殺 and 歳破 for the year — the directions traditionally avoided for moves and important journeys by everyone.

Your Personal Afflictions

Add your birthdate to also flag your 本命殺 (where your birth star sits this year) and its opposite — the directions to avoid that are specific to you.

Favourable Directions

Each direction carries the five-element relation between its star and yours, so the year-level candidate auspicious directions are easy to read.

Key terms

年盤 (Annual chart)
The Luoshu magic square rotated so the year's ruling star sits in the centre, giving the arrangement of all nine stars across the eight directions for that Nine-Star year.
五黄殺 (Goō-satsu)
The direction where the destructive 5-Yellow star has landed for the year — a direction avoided by everyone.
暗剣殺 (Anken-satsu)
The 'hidden sword' — the direction directly opposite the 五黄殺, likewise avoided.
歳破 (Saiha)
The 'year-breaker' — the direction opposing the year's zodiac animal (e.g. a Dragon year opposes the North-West).
本命殺 / 本命的殺
Personal afflictions: the direction where your own birth star has landed this year, and the direction opposite it.

API

The askTIAN Nine Star Ki Directions endpoint builds the annual chart (年盤) for any date and marks the afflicted directions of 方位取り. It computes the Nine-Star year with the exact 立春 boundary (the Sun reaching 315°), rotates the Luoshu magic square so the year's star sits in the centre, and returns all nine stars across the eight directions with the universal afflictions (五黄殺, 暗剣殺, 歳破) flagged. Supply a birthdate and it also computes the birth star and the personal 本命殺 / 本命的殺, plus the five-element relation between each direction's star and yours — surfacing the year-level candidate auspicious directions. The arithmetic is exact and gold-locked against the published 2024 (三碧) chart. A best-effort LLM reading is returned in parsable sections (set interpretation:false for structured data only). Honest rails: the annual chart and afflictions are exact, but a full directional judgement also consults the monthly chart (月盤); symbolic, and not travel, medical, legal or financial advice.

Endpoint: POST /trpc/kigaku.directions — 3 TIAN Points. See the API documentation and Playground.