Sukuyodo: Japanese Lunar Mansion Astrology
Sukuyodo (宿曜道) came to Japan in the 9th century with esoteric Buddhism, based on the Sukuyo-kyo sutra of 759. It uses 27 lunar mansions. Your birth mansion (honmei-shuku) is found from your birthday in the old Japanese lunar calendar, and its relationship with other mansions describes how people and days affect you.
The 27 mansions
昴 Bō · 畢 Hitsu · 觜 Shi · 参 Shin · 井 Sei · 鬼 Ki · 柳 Ryū · 星 Sei · 張 Chō · 翼 Yoku · 軫 Shin · 角 Kaku · 亢 Kō · 氐 Tei · 房 Bō · 心 Shin · 尾 Bi · 箕 Ki · 斗 To · 女 Jo · 虚 Kyo · 危 Ki · 室 Shitsu · 壁 Heki · 奎 Kei · 婁 Ro · 胃 I
The mansion of the first day of each lunar month is fixed (month 1 starts at Shitsu, month 2 at Kei, and so on), and the mansions then follow day by day. Leap months use the same starting mansion as the regular month.