Ja'far al-Ṣādiq (English spelling)

Japanese: Ja‘far al-Ṣādiq（英語表記）JafaralSadiq

…A radical Shiite sect of the Twelver sect of Islam. The sixth Shiite Imam, Ja'far al-Sadiq (c. 699-765), appointed his eldest son, Ismā'il (?-760), as his successor, but because of his bad habits, such as drinking, he revoked the appointment and appointed his younger brother, Musa al-Kāẓim (c. 745-799). The eldest son died in 760 while his father was still alive, but some who did not accept the revocation of the appointment claimed that Ismā'il was the seventh and final Imam, and were called the Heptāmists. …

From the Twelver

…the main sect within Shiite Islam. Along with the four orthodox schools of Sunni Islam, it is sometimes called the Ja'far school of jurisprudence, named after the sixth Imam, Ja'far al-Sadiq (c. 699-765). It has been dominant in Iran since the Safavid dynasty made it the state religion until the present day.

*Some of the glossaries that refer to "Ja'far al-Ṣādiq" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…イスラムの十二イマーム派の分派で過激シーア派。シーア派第6代イマーム，ジャーファル･アッサーディクJa‘far al‐Ṣādiq(699ころ‐765)は長子イスマーイールIsmā‘īl(？‐760)を後継イマームに任命したが，飲酒などの悪癖があったため任命を取り消して弟のムーサーMūsā al‐Kāẓim(745ころ‐799)を任命した。長子は父の存命中760年に没したが，任命取消しを認めない一部の者たちは，イスマーイールこそ第7代イマームであり，最後のイマームであると主張し七イマーム派と呼ばれた。…