Hogyo (demise) (崩御)
Hogyo refers to the death of emperors, czar, kings, grand empress dowagers, empress dowagers, empresses, and other monarchs euphemistically and respectfully. It does not matter why they died.
It is derived from a Chinese word and there is a sentence, 'The death of emperors is called 崩 (ho), the death of lords is called 薨 (ko), the death of daibu (master) is called 卒 (sotsu), the death of warrior is called 不禄 (furoku), and the death of ordinary people is called 死 (shi)' in the Kyokurei volume of "Book of Rites". The word may be used for demise of kings of other countries in newspaper articles.
It may be represented as 'hide'. This expression is used for the Japanese Imperial family because there is an idea that the emperors are descendents of gods in the Japanese mythology and are different from ordinary people. Another theory says that it is derived from an idea that the emperor is a descendent of Taiyoshin (the sun god), i.e., 'demise of the emperor means that the sun hides behind a cloud'. The word 'Kumogakure' (hide behind the clouds) is now used to mean disappearance, but it is originally derived from this idea.
薨去 (Kokyo) is used to express the death of people next to the emperor in rank, for example, imperial family members, such as crown prince, crown princess, imperial prince, and imperial princess and people higher than Sanmi (Third Rank) in the rank. At the emperor's demise, 'the Rites of an Imperial Funeral' is performed as national event.
In addition to 崩御, honorific languages, such as 薨御 that means the death of crown princes and ministers, 薨去 that means the death of imperial princes and persons with Sanmi or higher, and 卒去 that means the death of kings and princesses, and people higher than shii (Forth Rank) or goi (Fifth Rank) in the rank were used to express the death of nobles under the ritsuryo system. Another main honorific language of death is 逝去.
The demised emperor is called Taiko-Tenno during the period from his death to the determination of his posthumous title.