Chuin (中陰)
Chuin and chuu refer to the period of mourning lasting seven weeks in Buddhism. It is believed that during this period a dead person travels to the other world. It is the same as shijukunichi (the 49th day from the date of one's death). As a dead person is considered to reside in between life and death, and yin (shade) and yang (sun), this period is called chuin (on the way to yin).
Jodo Shinshu (the True Pure Land Sect of Buddhism) holds that the deceased turns into Buddha (various Buddha). Based on this thought, during the chuin period, those involved are supposed to cherish the memory of the deceased, think about 'life and death,' discipline themselves, and seek Buddhism.
Summary
In Buddhism in India where it originated, they used to give the memorial service every seven days for seven weeks, counting the date of death (anniversary of death) as the first day.
(Following the septal notation used in ancient Indian civilization, the period is defined in base 7.)
According to the philosophy of rinne (a belief in reincarnation), on the forty-ninth day after death, that person should reincarnate into which world of the rokudo(Six Realms of Reincarnation).
As during these forty-nine days, the soul hovers in between the old and the next lives; that state is called 'chuin' or 'chuu.'
The idea was imported to Japan and, although there are differences among sects, it is generally believed that a person dies, walks through the path of chuin in order to purge his/her soul, and turns into Buddha, aiming at the other world. On his/her way, there are gates of judgment here and there where the sins committed during the life are tried. A person who dies with serious sins will be made to fall into hell. If the bereaved gives memorial services, and if the judge can hear the prayers, the deceased will be forgiven. The details of the memorial services given every seven days are described below. The first monthly anniversary of the death comes between the fourth and the fifth weeks' memorial services.
List of Chuin Memorial Services
Shonanoka (a memorial service on the seventh day after one's death)---'Shoganki (the 7th day from the date of one's death)'
Futananoka (the fourteenth day from the date of one's death)---'Ihoki (the 14th day from the date of one's death)'
Minanoka (the 21st day from the date of one's death)---'Shasuiki (the 21st day from the date of one's death)'
Yonanoka (the 28th day from the date of one's death)---'Agyoki (the 28th day from the date of one's death)'
Shogakki (the first monthly return of the date of one's death)---First monthly anniversary after the death
Itsunanoka (the 35th day from the date of one's death)---'Shorenki (the 35th day from the date of one's death)'
Munanoka (the 42nd day from the date of one's death)---'Dankoki (the 42nd day from the date of one's death)'
Nanananoka (the 49th day from the date of one's death) (Shijukunichi, Man chuin, Jinshichinichi)---'Dairenki (the 49th day from the date of one's death)' is thought to be the most important memorial service.
The memorial service is best given on that day (or the eve of the day, depending on the region). If it is not convenient to have the service on the date, however, it is generally given earlier.
Kiake' or 'kimei' (end of mourning) refers to the fiftieth day the date of death inclusive.
Emma Daio arrives on the fifty-seventh day.
Mitsukigoshi is "a popular custom that Chuin must not exceed three months."
By the forty-ninth day, ihai (Buddhist mortuary tablet) should be replaced from the 'plain wood' one used at the time of the funeral by the real one.
Since ihai is not used in Jodo Shinshu, Hon ihai will not be made, but homyo jiku, homyo (priest's name or posthumous Buddhist name) hanging scroll should be obtained.