No named horoscope prepared by an immature technology of sky observation in the wet weather in Japan
with a faulty edited calendar of those days might not have any historic value except for the fact that
we see
the horoscopic chart was made by the description of a book translated from TETRABIBLOS of PTOLEMY imported. 
As the public reputation on this imported art was so high that the description of the famous world oldest private
story of GENJI-MONOGATARI written by SHIKIBU MURASAKI a woman novelist in the eleventh century has told the story on
the reason of failure to gain the high rank in the palace due to the ill prophesy indicated by the birth horoscope made
by the SUKUYO of the art imported.
We could find in every place in the world where people were conservative that
the public reputation of fortune telling art was high even if we saw no logical reason to support but the art was
tactical announced in a high value by a skilled practitioner of the day. The further problems in the absence of literatures
either in China or Japan on the precession shift of stars observed in the sidereal type calendars must be noted. Insufficient development in the art of sky observatory in Japan has made a shameful error in the report on the sky
phenomena in April 27 1686 made by the Moon and Venus conjunction observed. HARUUMI SIBUKAWA the chief
observatory of Tokugawa regime has announced the sky phenomena in error. He claimed that he was the first person
in the world who found the planet Venus has passed through the orbit settled in the space between the earth and the Moon.
He was an expert of the study on the calendars but his art in the sky observation was very poor. It had been a long durable
practice of Japan since Medieval Age to look upon more on the description of calendars than the observation of sky phenomena.
When the art of PROLEMY was introduced in Japan through China in 956 AD; they did not recognize the astronomy
of HIPPARCHOS developed.
But they only studied the practice of prediction without having any elemental study of
astrology explored.
Any calendar system with a fixed point of equinox will find almost one degree shift in the place of planet
during one hundred years elapsed. A person believes only on the description given in a calendar may find his prediction system useless after years elapsed.
にもとづくホロスコープの学問的価値はあります。この不正確な
ホロスコープでも、当時は新技術としての評判が高い存在であったようです。十一世紀作という、世界最古で
女性作家・紫式部作の小説・源氏物語の主人公・光源氏は宿曜（すくよう）の教えによって出世ができなかったと記述されています。
占いの根拠が学問的に不明瞭でも、取り扱う占い者の勘で、結果が大衆に取り入れられて流行するという例は
閉鎖的な社会ではよく見られることです。固定した春分点の暦と天体位置の変化を記載した文献が中国大陸にも日本にも存在しないことも問題です。